Digital Audio Onstage


The more widespread computers have become in performance, the more wide open their uses. Some computer performances expand upon conventional techniques. There are keyboardists playing soft synths, guitarists using computers for effects, turntablists using real vinyl to scratch digital files, and drummers hitting pads to trigger cues in a flexible backing track. Other possibilities include:

  • Sampling an instrument or voice and manipulating layers of loops

  • Creating improvised, mashed-up soundscapes by remixing samples

  • Assembling a custom piece of software for creating sounds, mixing beats, and generating musical patterns

  • Running theatrical cues (sound, music, and even video and lighting)

  • Manipulating visuals in time with music (VJing)

  • Using sensors and home-built physical controllers to generate interactive music

Despite such a wide range, you may be surprised at how much computer performersfrom the rock guitarist to the DJ to the experimental sound composerhave in common.

The main challenge all computer performers face is to adapt software and hardware tools, most of which are intended primarily for a studio environment, to playing live in front of an audience. This requires that you set up easy-to-see onscreen setups and easy-to-play hardware controls, so that you have access to what you need at the touch of your hands or feet.

Certain tools work well for many kinds of live performances. Software like Ableton Live is popular with musicians in divergent genres because it can perform tasks normally associated with DAWs and samplers in real time onstage, and has an interface that's easy to see and control while performing. For those willing to invest time in making their own custom performance tools, modular environments like Cycling '74 Max/MSP (www.cycling74.com), Pure Data (www.puredata. info ), and Native Instruments Reaktor (www.native-instruments.com) can help tailor the computer to fulfill almost any set of needs without the necessity of writing a line of actual programming code. Many performers have musical techniques in common, too. DJs were among the first to manipulate audio in performance, and some of the methods they have developed are reflected in a broad cross-section of musical genres.

Underneath all of these techniques are specific applications of technologies we've already looked at. MIDI is still the most readily available way to translate physical gestures into musical control. The ability to control the virtual world of the computer with physical movement is essential to making a computer a performance instrument, even if the movements are as simple as playing a QWERTY keyboard in a dramatic, virtuosic way. And the basic techniques of synchronization, used by many performers, are key to making events onstage match musical time.

Hooking Up to the House: What to Bring

Anyone who's ever been on the road knows the variability of house P.A. systems, but there are a few measures you can take to prepare:

Bring lots of cables: A set of cables and adapters will ensure that you're ready to plug into whatever you find.

Bring a power strip: A good quality power strip can guarantee that you won't generate your own ground loop and will help protect your equipment from unreliable wiring.

Stay balanced: Use an audio interface with balanced outputs if you can. You can also plug audio outputs into a DI (direct injection) box to balance the audio output.

Multiple outs: A multichannel audio interface can help you feed "front of house" speakers, onstage amps (for guitars, bass, and keyboards), and additional speakers that might be available, and help you control the mix yourself.

Consider a portable mixer: Having a mixer along can help with routing; aside from stand-alone mixers, there are various inexpensive portable mixers from makers like Alesis and Mackie/Tapco with self-contained audio interfaces. Audio interfaces like the 8-channel MOTU Traveler and 4-channel Lexicon Omega double as self-contained mixers, too.

If you want to record your set, you might consider bringing a portable recorder. In addition to lossless HD MiniDisc recorders, consider portable CompactFlash-based recorders like the Edirol R-1 or M-Audio MicroTrack. These players have decent mic inputs, line inputs, and (in the case of the MicroTrack) digital inputs, and record to increasingly affordable removable media. If you just need a line output from the board, the Gemini iKey (www.geminidj.com) lets you attach a USB 2 flash drive, portable hard drive, or hard drive-enabled music player to record a line input, with full start/stop and level trim controls. (Many DJ mixer/audio interface combinations also support bidirectional recording, so you can capture your performance or DJ set.)

Sadly, most digital audio players like the Apple iPod lack high-quality line-in recording capability. The iPod can be hacked to support better recording via a minijack by installing iPodLinux (www.ipodlinux.org). If you can settle for MP3- or WMA-encoded files (which are fine if you just want to post your set on your Web site the next day), you'll also find line-in recording on select players from makers like iRiver (www. iriver .com), Creative Labs (www.creative.com), and Cowon (www.iaudio.com).

If you're using software like Ableton Live or Propellerhead Reason that lets you easily record MIDI and arrangement actions, don't forget to hit Record while performing your set. Since in most cases you won't be recording audio, you can preserve some of your performance without having to use up significant hard-drive space or system resources.


The process of preparing for a performance begins with some basic questions. What do you want to be able to control directly, and what do you want the computer do for you (for those tasks for which you don't have enough hands and feet)? For the elements you want to control, what's the best interface for making your performance expressive and fun?

Live Instruments

A big draw of having a laptop onstage is being able to play your collection of software synths live. A keyboard or other MIDI instrument and a computer are a viable choice for replacing or supplementing outboard hardware synths and instruments. With a little preplanning, they can make it easy to call up, play, and manipulate a broad arsenal of sounds. All you need is a low-latency audio interface for the computer and a MIDI input to the computer (possibly in the form of a USB output from the keyboard), and you're ready to go.

Switching sounds

Your primary need onstage is probably being able to easily play different sounds. Using a single soft synth, that means being able to switch patches. If your soft synth lets you create different folders of patches, it's a good idea to copy the patches you intend to use (or a selection of favorites) into a separate folder to make them more manageable. To avoid having to click the mouse, assign the "next patch" or "next program" control to a MIDI parameter. In Propellerhead Reason, for instance, the "next" and "previous" patch controls are MIDI-assignable, so you can scroll between them with MIDI buttons ( Figure 13.1 ). In Reason 3 or later, you should assign these buttons to a folder of Combinator patches, since that module can contain any combination of Reason's devices.

Figure 13.1. Assign the program change control to a MIDI controller, and it'll be easy to change patches on your soft synth without using your mouse or computer keyboard. In Reason, the next and previous program controls are configured by default for keyboards that support Reason's Remote communications protocol, but you can create your own assignments, which you can access via Options > Remote Override Edit Mode. If you're using Reason 3 or later, set up all your patches with the Combinator so you can easily control splits , layers, and MIDI assignments for any of Reason's built-in synths.

When using multiple instruments, it's often easiest to set up each instrument on its own MIDI channel. Most hosts will use processor resources only if a signal is being generated by the plug-in, so you can switch which instrument you're playing by switching which channel is enabled for MIDI input, or change the MIDI transmit channel on your master keyboard. For instance, you might put a piano sound on the first channel and an organ sound on the second channel. In Ableton Live, you can switch between sounds by assigning the record-enable for each track to a different button on your keyboard or foot pedal. If you're using Steinberg Cubase as a host, you can use the computer keyboard's up and down arrow keys for switching. Other programs may require a little mouse work.

Mapping MIDI to QWERTY: Do you have a software control you want to use during performance, but it includes only QWERTY keyboard shortcuts and doesn't allow MIDI messages to be mapped to commands? On the Mac, you can use MIDI to trigger keyboard shortcuts (and even AppleScripts) with MidiPipe (http://homepage.mac.com/nicowald/SubtleSoft). On the PC, you can create extensive mappings of incoming MIDI messages to QWERTY keystrokes, assignable to different programs, using the "postcardware"/EUR20 Bome MIDI Translator, shown in Figure 13.2 (www.bome.com).

Figure 13.2. Bome's MIDI Translator for Windows can remap incoming MIDI to other MIDI or to keystrokes. It's useful for bridging the divide between hardware and software that aren't designed to work with each other.


If your keyboard is doing double-duty, both generating its own internal sounds and controlling sounds on your computer's soft synth, you can switch between them using a hardware mixer, or, if your hardware synth is routed into software, the mixer in your DAW. That way, to switch from one to the other, you can grab a mixer fader instead of having to work with the menus on your synth. (Note that you may experience in-to-out latency issues routing analog inputs from a hardware synth when mixing with software. This is avoided with synths that include low-latency drivers for audio input like the Novation X-Station and Access Virus TI.)

Most of the time, you'll probably use your hardware synth's built-in program change controls to switch its sounds. But if you want automatic software control for quicker changes or automatic changes during the course of a song, you can store program changes in software and transmit them from the computer to the keyboard while the music plays. In Ableton Live, for instance, you can give each MIDI clip an associated program change: double-click a MIDI clip, and then select bank, sub-bank, and program numbers for that clip in the Note Box. (For more on bank select messages, see "Programs and Banks" in Chapter 8. Ableton's bank values correspond to the bank select MSB, and their sub-banks are the bank select LSB.) You can quickly fire off different patterns, each of which will transmit a different program number to your external synth. In Cakewalk's Project5, you can do the same by clicking on any MIDI track. (You'll need a different MIDI track for each program change.)

Playing multiple sounds

Program changes let you switch between sounds quickly and easily. But what if you want to play more than one sound at once?

One option is to use multiple input devices, each assigned to a different synth. For instance, you might place two or three keyboards on a multitier rack or use a keyboard and drum pad. Place different plug-ins on different tracks in your host (or different instances of the same plug-in with different patches loaded) and set the input of each to a different keyboard. (If the keyboards are plugged into different MIDI ports or use USB, you can select them by port. If they're chained together via MIDI, set them to different MIDI channels and set each track to the corresponding channel.)

To play more than one sound simultaneously from a single keyboard, you can use splits and layers. Splits assign different sounds to different areas of the keyboard, and layers assign multiple sounds to each note. (For more information on what splits and layers are and how to configure them, see Chapter 8.) There are several ways to set up splits and layers ( Figure 13.3 ):

  • Using your keyboard: You may be able to set up splits and other routing options on your keyboard. Most MIDI keyboards, other than the most bare-bones, entry-level models, can be configured to assign different key zones to different MIDI channels. This is usually the best approach if you want to play external hardware synths and soft synths at the same time.

    Vital MIDI tools: If your host of choice makes MIDI routing and data processing difficult or doesn't do what you need it to do, you'll need some extra tools to do the job. Try the donation-ware MidiPipe (http://homepage.mac.com/nicowald/SubtleSoft) on the Mac or MIDI-OX (www.midiox.com) on Windows. They'll handle tasks from the simple (splitting your keyboard between two soft synths) to the complex (microtones in MidiPipe or scripting in MIDI-OX).


  • Internally, in a soft synth: If your soft synth supports combination patches involving more than one sound, you can set up splits or layers within the synth. (SampleTank FREE, included on the DVD, supports combi patches, which are demonstrated in some of the included tutorials.)

  • Using your host: Many hosts have their own split and layer functions that work independently of the plug-ins. This can allow you to assign more than one plug-in at a time to a keyboard. (This technique works particularly well with hosts designed for hosting plug-ins for performance, such as V-STACK and Rax. Logic Pro's Environment, Cakewalk Project5, and Reason 3's Combinator all have extensive options for configuring layers, splits, and other MIDI options.)

  • Using an extra tool: If you can't accomplish what you want in your host of choice, you may want to combine it with another tool. Using MIDI-OX on Windows or MIDI Pipe on the Mac, you can perform splits, layers, and various routing tasks.

Figure 13.3. Mapping inputs can help you play more than one instrument at a time. Cakewalk's Project5 lets you configure which ports, note ranges, and even velocities go where just by clicking on an instrument. This makes Project5 an ideal host for playing live on Windows (1). Reason's Combinator lets you combine splits into a single instrument (2). If you need additional settings beyond what your software and keyboards provide, turn to a tool like MidiPipe on the Mac (3) or MIDI-OX in Windows.

Tools for hosting soft synths

If you're opting for plug-in instruments (rather than software with built-in instruments), you'll need a host environment. That can be your DAW or workstation software, which often has the advantage of providing its own built-in instruments and effects, plus arrangement and backing track features.

Alternatively, if you just want a simple way to host a couple of plug-ins, you can opt for a more basic plug-in host. There are several potential advantages to using a host: this type of software can be simpler to configure, less expensive, and more lightweight in terms of system resources. A host can also provide additional features. Some of the more useful possibilities include:

  • AU Lab (Mac OS X 10.4 and later; free): Apple's free testing tool for developers doubles as a surprisingly feature-rich Audio Unit host, with extras like side-chaining, custom channel strips and groups, MIDI splits, tempo controls, and network routing. Install the Xcode Tools option from your OS install disc; it can be found in Developer > Applications > Audio > AU Lab.

  • Rax (Mac; $30; www.plasq.com): Rax is a simple, reliable Audio Unit instrument and effect host and mixer. It's especially good at easy, powerful MIDI assignments, including layers, keyboard and velocity splits, and MIDI learn. You can even assign MIDI to those pesky plug-ins that don't support it natively. Rax supports audio input and has a built-in reverb as well.

  • Steinberg V-STACK (Mac/Windows; $50; www.steinberg.de): Using Steinberg's VST and ReWire host is a bit like having Cubase's channel strip and instrument routing, without the sequencer ( Figure 13.4 ). It has some handy effects send capabilities, preset management and keyboard splits, and network features via System Link. (Despite its name , it also supports DirectX instruments and effects on Windows, although not AU on the Mac.)

    Figure 13.4. Steinberg's V-STACK serves as a mixer and a host for effects and instruments (DirectX on PC and VST on PC and Mac). Used alone, it acts as a "mini-DAW" for live mixing and hosting. Steinberg's System Link lets you synchronize multiple machines and transmit audio and MIDI data, which is useful for multicomputer performances.

Several more sophisticated tools can also be used for hosting, adding in modular tools for building your own custom instruments. These tools are probably overkill if you just want a simple way of hosting a couple of soft synths or effects, but if you want to tinker with more advanced, "under-the-hood" MIDI and audio operations, they can be invaluable. In addition to options like Max/MSP, Reaktor, and Pd, other tools especially well-suited to the task include:

  • Buzz (Windows; free; www.buzzmachines.com): Buzz is popular as a performance tool because it's free, has a broad user community with lots of sample content, and doubles as a modular MIDI and audio environment, and synth in its own right. It can be complex to learn, but the payoff is some sophisticated custom patch design capabilities normally found only in environments like Max/MSP, Pd, and Reaktor.

  • Plogue Bidule (Windows/Mac; $75; www.plogue.com): Like Buzz, Bidule is a modular audio environment as much as it is a host. But because it supports cross-platform VST and Mac AU, as well as both ReWire slave and master mode and Open Sound Control (OSC), it's also popular as a performance host. It has some sophisticated audio and MIDI routing that make it useful as a Swiss Army knife tool. You may not need to perform spectral manipulations to the audio signal from your piano plug-in, but if you do, Plogue Bidule can handle that as well.

  • Energy XT (Windows; $50; www.xt-hq.com): Energy XT offers a little bit of everything. Its modular design lets you create splits, layers, and chains of instruments, but it also has a sequencer, an automatic chord generator, a piano roll editor, and envelopes. Some musicians use it simply as a host or a way of extending their existing tools; others use it as a more extensive environment, although it lacks some of the more advanced features of Plogue Bidule. Like the other programs listed on this page, it has a passionate user community.

Arpeggiators and Patterns

Using pattern-based software and arpeggiators, it's possible to "perform" complex rhythmic phrases that would be difficult or impossible to play yourself. You can use these for rhythmic pitched effects or to control effects and other parameters in sequence.

Arpeggiators

An arpeggiator is a special MIDI effect that automatically plays a sequenced pattern based on an input note or notes. In musical terms, an arpeggio is the notes of a chord played in a series from bottom to top or top to bottom rather than all at once. (It's also called a "broken chord"; the sound of a harp or guitar strum is a fast arpeggio.) In its simplest form, an arpeggiator plays the notes of a chord you're holding down in sequence.

You can use an arpeggiator for more dramatic rhythmic effects, however, depending on the parameters it provides. Different arpeggiator shapes or "styles" can be used for different effects, like playing up and down the chord in series. Some can play prerecorded , polyphonic patterns. By adjusting the rhythmic interval of the pattern or using an arpeggiator that's synchronized to tempo, you can create unique, rhythmic special effects.

Some arpeggiators can automatically generate chords as well as sequential patterns. It's the opposite of an arpeggio, really, but the term has come to mean any software effect that adds notes based on the ones you're playing. Some arpeggiators might best be considered "interactive pattern generators," because they're capable of generating various patterns based on input pitch. Up and down scales can get fairly boring, but with a full-featured arpeggiator or pattern sequencer, you can use arpeggiators to produce otherwise unplayable patterns.

Although an arpeggiator is most often used with a pitched soft synth, you can route an arpeggiator's MIDI output to any instrument or effect parameter with a MIDI input. For instance, applying an arpeggiator to a drum track can "mix up" a drum pattern or create doubling effects. You can even use an arpeggiator with a keyboard input to automatically control a MIDI-assigned effect, such as a filter, in an interactive way.

You can even use arpeggiator parameters as performance tools. The effect is somewhat less than subtle, but you can accentuate the pattern of the arpeggiator by assigning knobs or faders to parameters like the step length (the length of each arpeggiator note) or speed, and then adjust that knob during a performance.

Custom pattern generators

What if you're not happy with preset arpeggiator patterns or static pattern clips that aren't based on input pitch? You're a candidate for building your own custom interactive patterns.

Building a pattern generator: Try out a custom Mac/Windows interactive pattern generator/step sequencer built in Max/MSP (included on the DVD) and learn how it was built.


Modular environments like Pure Data, Max, and Plogue Bidule are all designed for the job. In fact, creating MIDI processing patches is often the best way to begin learning one of these environments, because such patches tend to be the simplest. For instance, you can create chords automatically using basic arithmetic: for each note-on event, use an "add" module to output an additional note event some number of scale steps higher. For a triad , use two add objects, each connected to an output object ( Figure 13.5 ).

Figure 13.5. Three approaches for controlling MIDI data live using custom software patches. Using basic arithmetic, you can patch together objects in software like Max/MSP to change notes (1). By building up various objects in this manner, you can create a custom pattern sequencer, for example, based on your own needs (2). Using prebuilt "macros" ( components of a larger patch) or " ensembles " (prebuilt instruments), you can jump-start custom performance software creation in Reaktor using objects like this step sequencer (3).

More sophisticated users may create elaborate random note generation algorithms. Taking the concept to the extreme, you can reduce your "performance" to pressing a single key. When designing your own pattern generator, keep in mind that you can use patterns to control any number of parameters, not just pitch.

Double duty: Switching between guitar or bass and keyboard parts? Since guitar effects like Guitar Rig, AmpliTube, and Line6's GearBox software run as plug-ins, try feeding your keyboard parts through them for some grungy effects. These effects can also create unusual timbres with string instruments like violin, cello, and sitar, and can create unique distortion effects with drums.


If the prospect of digging into a modular software environment is frightening, you can simply chain MIDI effect devices in Ableton Live. The Random effect, since it has a variable amount of randomness, is particularly useful for creating complex effects. You can also design rule-based pattern generators using MIDI-OX or MidiPipe.

Live Effects

By using software-based effects live, you can apply your full arsenal of sonic tools to both live audio input and recorded sources ( Figure 13.6 ). When effects parameters are manipulated onstage, effects become part of the performance. If you're just adding effects to existing elements, like loops, prerecorded audio materials, and soft synths, the process is fairly simple. You'll route effects just as you would for studio recording. (For more on using effects, see Chapter 7.)

Figure 13.6. A multi-effects package like the Line6 TonePort can help you emulate studio equipment when you're onstage. These packages are favored by electric guitar and bass players, but mic preamp models are ideal for vocals, and you can use the distortion, amps, and effects with other instruments, too. (Photo courtesy Line6, Inc.)

Live performance can pose two special challenges: how to minimize or manage the latency of live audio being sent to the computer, and how to easily turn effects on and off and control their settings in real time. (Note that you should be especially careful managing CPU load with Ableton Live, because, unless you've frozen tracks, it's also performing time-stretching in real time.)

Hardware first? If your computer is overburdened with live processing tasks, you can plug a live input into a hardware effects processor prior to connecting it to your computer or use an effects processor that's built into an audio interface. Examples include the inexpensive, MIDI-controlled Lexicon MPX 110 processor with a digital out (www.lexiconpro.com) and audio interface/processor combinations like the MindPrint Trio USB (www.mindprint.com) and M-Audio Black Box guitar processor (www.m-audio.com).


Live audio input and latency

With live input, signal must pass through the audio interface, through whatever software you're using, and back out through the interface again. As a result, the time lag (latency) becomes particularly significant. (If you're using your software for mixing, you'll face the same issue.)

Above about 1011 ms, latency becomes great enough that instrumentalists who are playing live will notice it. Generally, 3 ms is the minimum practical latency that can be achieved on computers; it's nearly undetectable. (The range in between is usually tolerable.)

You should double-check two basic elements for low-latency operation:

  • Low-latency drivers: On Windows, ASIO 2.0 drivers are your best bet for lowest latency. (Windows Vista will incorporate lower-latency drivers into the Windows Driver Model.) On Mac, drivers are essentially a non-issue; all Core Audio drivers are low latency. (That's assuming the drivers work, of course, but if functioning properly they should be low-latency.)

    Adding horsepower: A DSP hardware-based effect doesn't rely on your CPU, making it highly desirable in performance situations where your computer is handling a lot of tasks at once. Various effects, including live vocal and guitar processing, are available for the portable, FireWire-based PowerCore Compact system (www.tcelectronic.com), for instance. If you're using Windows, you might also consider the E-MU 1616M (www.emu.com), which includes a suite of DSP-based effects.


  • Low-latency settings: Some programs let you adjust the latency of the audio driver; obviously, for live audio applications, you'll want to err on the side of less latency. (See Chapter 4 for more on configuring your audio interface.)

Some effects plug-ins introduce more latency than others, so try auditioning different effects if one seems to be causing too much latency. Also, latency is dependent on the speed of your computer's CPU. A slower computer will run out of processing headroom more quickly when set to a low latency. This means that you may have to make a trade-off between low latency and running all of the effects or soft synths you'd like to. Native Instruments, for instance, recommends a relatively high- powered processor for live operation of its Guitar Rig live effects software (minimum 1.25 GHz Mac or 1.4 GHz PC).

Note that "latency compensation" or delay compensation features have no bearing on live audio input. They work with plug-ins only during track playback. See "Delay Compensation" in Chapter 7.

Turning effects on and off

Running effects constantly can quickly get unwieldy, both musically and in terms of CPU resources. If you're using insert effects in Ableton Live or plug-ins that support MIDI mapping, make sure you assign the bypass switch on your effect (or the enable/disable switch) to an easily accessible MIDI control. You can also assign sends to a fader for easy adjustment of level feeding the effect.

All about sends: You'll want to be even more mindful of using sends in live performance than when mixing prerecorded tracks. Using CPU-hungry effects like reverb on a send instead of multiple inserts will save computer resources, and it's often easier to assign a send level to an external MIDI control than it is a wet/dry level in an effect.


Using software effects doesn't mean giving up the easy footswitch method of enabling and disabling effects to which guitarists and bass players are accustomed. A MIDI pedalboard or foot controller can provide control. They're useful for laptop-based musicians who need their hands to play their instruments (like horn players, string players, and keyboardists), not just guitarists ( Figure 13.7 ).

Figure 13.7. A MIDI-only footswitch like the Behringer FCB1010 lets you add pedal control to any software that can be mapped to MIDI notes or control changes. The large pedals send continuous expression data (useful for controlling the level of an effect). (Photo courtesy Behringer Spezielle Studiotechnik GmbH)

Native Instruments' Guitar Rig includes its own pedalboard called the Rig Kontrol 2; IK Multimedia's AmpliTube is available with an optional StompIO controller. You can also use MIDI pedalboards to control these and other sets of effects.

Real-Time Control

With just two hands, two feet, and a performance to focus on, assigning live control of parameters to easily accessible knobs, faders, buttons, and foot pedals is essential. (See "Using Control Surfaces" in Chapter 8 for more information on choosing and configuring control surfaces.)

  • Combine controls: You can make a knob or fader do multiple duty by routing its control change output to multiple destinations. (This sometimes requires a third-party tool for remapping, since many programs let you map a controller to only one parameter at a time.)

  • Combine instruments: Many DAWs let you combine effects parameters, instrument settings, and so on into single settings for easier switching. Try features like Logic Pro's channel strip preset save and recall, Project5's device chains, Live's Device Groups and Live Clips format, and Reason's Combinator patches.

  • Combine changes: When changing from song to song, you may have a whole set of device changes that need to happen: fader changes, program changes for effects and synths, effects chains, and so on. You can combine these by loading a new song into your DAW or by inserting these events at a marker/locator position and triggering them that way. (In Ableton Live, you can use the "Macro Track" trick discussed later in the chapter.) If these methods don't work well, you can store changes in a custom patch in a program like Max, Pd, or Reaktor and launch them from there. It's not as elegant as having a prebuilt solution, but unlike the frequent frustration of having to rely on developers, you're guaranteed it'll work the way you want since you built it yourself.

It's useful to have a "tool belt" for handling MIDI routing and assignment chores. Some routing tools may be included in the program you're using. Logic Pro's Environment, although initially daunting, can be used for sophisticated MIDI routing and automation tasks. For instance, you can combine a number of changes to instruments and effects into a selector patch, as shown in Figure 13.8 . Hosts like Plogue Bidule and EnergyXT also have modular MIDI routing and assignment tools.

Figure 13.8. A power-user approach to the problem of switching between instrument and effect settings is to create a virtual patch bay to route notes and change parameters, as in this custom Environment for Apple's Logic Pro. (File courtesy of Christopher Scheidel, www.heavyliftmusic.com)

Controlling FL Studio: FL Studio provides some powerful hooks for external control. You can use a Logitech gamepad (www.logitech.com) like the Cordless Rumbleman 2 with FL Studio's X-Y Controller ( Figure 13.10 ). With two analog joysticks, you can control two Fruity X-Y Controllers at once for control over four parameters. Also try the unique Peak Controller to have peaks in a mixer automatically control some other parameter (like a synth or plug-in).


Game on: For game controllers in other applications, try the hi object for Max/MSP or junXion for Mac OS X (www.steim.org/steim/junxion.html).


The other option is to use a tool to intercept MIDI data between your input device and your software of choice. MIDI-OX on Windows and MidiPipe on Mac both work well for basic MIDI routing and assignment. If that's too limiting, you can also build your own custom tool in a program like Max/MSP or Pd.

Need a spare screen? If the Lemur multi-touch interface exceeds your budget (see p. 325), you still have other options. You can find affordable single-touch touchscreens for quickly navigating parameters from vendors like ELO Touch-Systems (www.elotouch.com) for as little as $300. If visual feedback is all you need, so you can tell what you're doing with your MIDI controller, Lilliput Electronic (www.lilliput.com) makes tiny LCD screens designed for use in automobiles that you can place discreetly on your rig.


One especially useful tool on Windows is PeterTools LiveSet (www.petertools.com), a Reason-like rack of MIDI tools. It includes multiplexers for manually creating layers of synth and effect controllers, transposers, chord players, and a MIDI routing module, among other elements ( Figure 13.9 ). LiveSet is clearly designed to work with Reason, but it works equally well with other software that benefits from these features; it's compatible with any Windows ReWire client.

Figure 13.9. LiveSet (left) is a Windows-based ReWire host that fills in a lot of the performance MIDI features other applications lack. It includes a collection of devices that can combine MIDI control, facilitate custom routing to soft synths, create chords, patterns, and loops, and handle other tasks. Just as in Reason, press the Tab key and you can create custom signal routings (right), which are vital for getting your MIDI data to go where you want.

The Joy of X and Y

X/Y controllers can be especially powerful because they let you control two effects parameters at once, like cutoff and resonance of a filter, or delay time and wet/dry level of a delay or reverb. You'll find X/Y touchpads on hardware like the Novation X-Station and ReMote, Korg Kaoss Pad, and joysticks on many keyboards. To manually assign these to two parameters, turn on MIDI learn and assign each axis separately by moving or touching the controller carefully in a single direction. Software tools like the Fruity X-Y Controller in FL Studio ( Figure 13.10 ) and the X-2 Cross-fader in PeterTools LiveSet provide additional options.

Figure 13.10. X/Y controllers give you simultaneous control of two parameters. You can use FL Studio's X-Y Controller with a mouse, but it's more fun with joystick input.


If you lack an X/Y controller, the Mercurial Innovations STC-1000 is worth a look. It's a specialized MIDI touch controller that can work in an X/Y mode or double as a 16-zone percussion-style trigger (www.thinkmig.com).


Synchronization

Once you start playing with multiple software applications, multiple pieces of music gear, or multiple computers, you'll probably want to sync everything to a single tempo to keep all your gear and software in time. By using synchronization, you can:

  • Sync two pieces of software on the same computer. (Example: one piece of software running a soft synth arpeggiator is synced to another piece of software running drum loops.)

  • Sync your computer to external hardware. (Example: an external drum machine or loop sampler with a tap tempo button controls the tempo of a computer running loops, patterns, or backing tracks.)

  • Sync your external hardware to your computer. (Example: VJ hardware running live video clips is synced to the tempo of a music program.)

  • Sync two computers to each other. (Example: you and a friend play a computer duet with tempo-dependent effects that are synced.)

Tempo master and slave

Common to all these techniques is the need to have what is usually called a single "master" and one or more "slaves" for tempo. You need a single piece of hardware or software to act as the master, setting the tempo for all of the other pieces of hardware and software and transmitting the necessary clock information to the slaves on a continual basis. There can be only one master. If you had more than one, it'd be like having more than one conductor running a symphony orchestra. You can have any number of pieces of hardware and software following the tempo, but only one can set the tempo.

ReWire

Plug-ins are able to route MIDI and audio to a host, and some are able to synchronize timing to the host tempo (for tempo-synced delays, for example). If you want to use different stand-alone applications for this task, however, you need ReWire . ReWire is a technology developed by Propellerhead that has become an industry standard for interconnecting different pieces of software on the same machine. ReWire transmits the following data:

  • Synchronization: Tempo, meter, start/stop, position within an arrangement, looping on/off, and loop start and end points.

  • Audio: Multichannel audio (both independent audio channels and a left/right master mix).

  • MIDI: Multiple simultaneous channels of MIDI performance and/or control data.

  • Device labels: Instead of channel numbers, connected slaves will show the names of soft synths, drum machines, and the like. (This feature is found in ReWire 2 and later.)

In other words, you have full audio and MIDI routing, and complete control over the transport. Synchronization is sample-accurate (a far cry from MIDI clock, as you'll see in a moment), and once a ReWire client is loaded into the host application, the management of resources is handled by the host. A client ReWired into a host takes up fewer system resources than the two would on their own, and they're able to share a sound card and external sync settings (controlled by the master).

Unlike other synchronization methods, ReWire accomplishes all this transparently without your intervention. The process sometimes confuses beginners because you don't have to do anything with most applications to make ReWire work. The process is simple ( Figure 13.11 ):

  1. Launch the host application first.

  2. Launch the client application second. (The order is crucial; otherwise, ReWire won't work.)

  3. Route audio and MIDI. (You may need to switch on ReWire audio reception or record-enable an audio track in the host in order to monitor the signal coming from the ReWire client; otherwise, audio may be properly routed but you won't hear anything.)

Figure 13.11. ReWire can extend your available software instruments without taxing system resources. Reason, for instance, can be loaded into Live so you can play synths from Reason together with synths, audio loops, and MIDI patterns in Live. In this example, to access just one synth we've routed the left/right audio output mix from Reason into a Live track while routing a MIDI track back to the Reason synth so it can be played by Live's MIDI patterns.

A common usage of ReWire is to set up the host application as "mixer," controlling tempo and backing track arrangements, and a client application as the "instrument" for adding a synthesizer, virtual instrument, drum machine, sampler, arpeggiator, or other instrument that isn't available in the host application. (You'll sometimes even see the terms "mixer" and "instrument" in place of master and slave or host and client, although the latter is more common.)

For audio and MIDI routing, depending on your host's ReWire implementation, you should have several options. If you just want to play a client as a synth, you may just route the left/right audio mix into your host. If you want multichannel control of each separate output, you can route channels independently into your host. If you want to play MIDI patterns from a program like Live or Project5 back into the ReWire client, set a MIDI track output from your host to the input of your client.

One particularly popular combination is the use of Propellerhead Reason with Ableton Live. Live provides the audio input, more extensive loop, pattern, and arrangement triggering, arpeggiator, and MIDI tools that Reason lacks, while Reason fills out Live's built-in instruments with a healthy collection of samplers, drum machines, and synths. That's just one example, though; the appeal of ReWire is being able to mix and match any applications you like. Some examples of applications with ReWire support include:

  • Host ("mixer"): Digidesign Pro Tools, Apple Logic Pro, Apple GarageBand, MOTU Digital Performer, Steinberg Cubase and Nuendo, Cakewalk SONAR, Adobe Audition, Steinberg V-STACK

  • Client ("synth"): Propellerhead Reason, Cakewalk Kinetic, ArKaos VJ

  • Both host and client: Ableton Live, Cakewalk Project5, Cycling '74 Max/MSP, Plogue Bidule, Arturia Storm, FL Studio, Sony ACID (Pro version 5 or later)

If an application can run as either a host or a client, its role will depend on the order in which it is loaded. For instance, if you load Live and then load Max/MSP, Live will be the host and Max the client. If you load Max and then load Live, Max will be the host and Live the client. Usually, you'll use only one client at a time, although some hosts can support more than one client at once. As with other sync methods, there can be only one master clock source, so two hosts can't operate together.

Testing ReWire: If you don't hear anything, make sure you've set up an audio track to receive audio from the ReWire slave and have record-enabled that track and/or turned on monitoring. (A good source to try for testing is the master L/R input from the ReWire slave, because it mixes all the audio channels from the slave together; you don't have to worry about selecting the right channel.)


ReWire gives you significantly more control than other synchronization methods. It does require that all the software be running on the same machine. For information on how to synchronize between computers, see the upcoming sections, "MIDI clock synchronization" and "Networking computers and distributed computing."

If you want to use stand-alone applications that don't support ReWire, you can use MIDI data routed between the applications; see "MIDI clock synchronization." Some applications that don't support ReWire, such as Native Instruments Reaktor, can instead be loaded as plug-ins. Plug-ins share many of the advantages of ReWire, including clock sync. For more information comparing ReWire to using plug-ins or stand-alone applications, see "Combine software for a custom studio" in Chapter 2.

Pure Data and Jack: The free interactive application Pure Data (Pd) doesn't support ReWire, but it does work with interapplication MIDI drivers like the IAC driver on Mac and MIDI-Yoke on Windows. On Mac and Linux, Pd also supports Jack, which allows synchronous interapplication audio (jackit. sourceforge .net).


MIDI clock synchronization

The easiest and most reliable way of providing synchronization between devices is with MIDI clock. Most often, MIDI clock is used to synchronize hardware to hardware or hardware to software rather than software to software. You'll need devices capable of sending and/or receiving MIDI clock data, and they'll need to be connected using MIDI cables (or via MIDI over USB or FireWire).

You can synchronize different software applications using MIDI clock. On the Mac, use the Inter-Application Communications driver or a virtual MIDI driver. On Windows, use MIDI Yoke. (For more information on utilities to use with Windows and Mac for MIDI, see "Essential MIDI Tool Belt" in Chapter 8.)

For a full explanation of how MIDI clock works, see "MIDI Time Code and MIDI clock" in Chapter 8. With that in mind, let's look at the specifics of how MIDI clock is relevant to performance.

It's important to understand what data a MIDI clock connection transmits:

  • Start and stop

  • Position and "continue" (to start playback from a position)

  • Tempo

Tempo isn't transmitted explicitly: the master doesn't transmit "120 bpm" to receiving devices. Instead, the MIDI clock signal consists of a regular "pulse" of messages at a resolution of 24 pulses per quarter-note. The receiving device has to count those 24 messages, or at least measure the time gap between two of them, before it knows what the tempo is. It's a bit like watching a conductor: the conductor doesn't say, "okay, we'll do this at 133.34 bpm." Instead, musicians simply watch the steady pulse provided by the movements of the conductor's hand.

A resolution of 24 messages per quarter-note (24 PPQN) is significantly less than the MIDI editing resolution of most audio software, but it's enough for performance synchronization. You'll encounter sync issues only if you make tempo changes that are too sudden. You might not want to go from 40 bpm to 240 bpm instantaneously, for instance. Gradual tempo changes, or small intervals, will usually work fine.

You can use the combination of tempo data and start and stop messages to quickly sync software, computers, and hardware. Here's the basic process:

MIDI clock, not MIDI Time Code: Make sure you're syncing with MIDI clock, not MIDI Time Code (MTC). Many software applications will let you use either type of synchronization. MTC is intended for transmitting time data in seconds and frames . That's useful for syncing with video devices, but useless for musical performances (or even performing with musically synced video, as VJs do). If two tempo-based devices are synced using MTC, each will have its own tempo control and can speed up or slow down independent of the other. MIDI clock gives you musical tempos and pointers to song position.


  1. Choose a MIDI clock master. Designate a piece of hardware or software for transmitting MIDI clock. Not all devices and applications have both send and receive capability; some have only receive capability. (Propellerhead Reason can only receive, for instance, although you can load it as a ReWire slave and use your ReWire host for MIDI clock transmission.)

  2. Connect your gear. Connect all of the gear you need to receive MIDI from the master. Multiport MIDI interfaces can be handy if you have a complex hardware setup, but for most setups you'll just need the usual MIDI cables and/or USB/FireWire connections.

  3. Configure the sending device. Most software (including Ableton Live and DAWs like Cakewalk SONAR) will let you choose the ports to which you want to transmit synchronization data.

  4. Configure the receiving devices. You'll need to set sync to "external" for each receiving device to receive MIDI clock. Once you've done this, depending on the device, certain features (such as an arpeggiator) may operate only when MIDI clock messages are actually being received. When the master clock source is stopped , the synchronized device may produce unexpected sounds, or even no sound at all.

  5. Start me up. Once you're ready to go, hit play. If you want to adjust the tempo during a performance, you can do so with a tempo control or by tapping in a tempo (see "Tap tempo," below); all the receiving devices will stay synced. Hit stop, and all the devices will stop.

Hardware patterns at the ready: MIDI clock can help you integrate hardware and software. Using a device like a Korg ElecTribe, for instance, you can store song patterns and tempo-synced parameter automation in "Pattern Sets" and call them up using the front-panel button devices. In external sync mode, they'll sync to your computer or other clock source. When it's functioning as a MIDI clock master, ElecTribe lets you use the pattern buttons containing different tempi to trigger your computer sequence or other devices.


If you want to get a little fancier and have software and hardware that support it, you can use MIDI clock to locate to specific points in an arrangement or to select songs using position and song select messages.

Not all devices support position messages (called Song Position Pointer, or SPP), but most recent devices that support MIDI clock do. Position is defined in terms of the number of sixteenth-notes since the start of the music. But you're probably only jumping to a downbeat in a performance anyway, so the fact that you can't locate to a position between sixteenth-notes is unlikely to matter. You can use SPP to jump to certain parts in a arrangement if you have a sequence in a piece of software that's synced to a drum machine pattern, for instance.

Most hardware devices also support a song select message, which lets you jump to a specific song. For example, you can store various patterns on a piece of hardware like a Korg ElecTribe and call them up by transmitting song select messages. (Software is less likely to receive this message, but some sequencers that support subsequences and MIDI remote control do.)

Tap tempo

Depending on the features of your software, you can set a tempo by typing a number directly into a tempo box, turning a knob on a control surface assigned to the software, or using the tempo controls on a piece of hardware that's transmitting MIDI clock. For dynamic control of tempo, however, tap tempo is the way to go. By pressing a tap button on hardware or (better yet) assigning hardware or software tap tempo to a MIDI foot pedal, you can set a tempo for your gear much the way you would do a countoff for your band . (You'll find a handy tap tempo button in Ableton Live.)

Using tap tempo, you can dispense with other synchronization methods altogether. For instance, a VJ or electronic musician might follow a live instrumental performance by an acoustic jazz quartet by tapping along to the tempo manually. (You can either tap continuously through the song or simply tap to set a tempo and leave it there, then begin tapping again when the tempo needs adjustment.) One advantage of this method is that it allows you to synchronize with live instruments. (An acoustic jazz quartet is made up of human beings without a MIDI out port!) But it can also be used with electronic instruments to keep the tempo feel of a performance loose and improvisatory.

Networking computers and distributed computing

MIDI and audio are ultimately just data, so there's no reason the "pipe" for the data can't be a network. The reason we're not all using Wi-Fi-enabled MIDI and audio for performance is synchronization: keeping data in perfect sync while it's transmitted over a busy network is a challenge. Although there's still no major standard for networked transmission of MIDI and audio, you can accomplish the task with specialized tools.

An additional benefit becomes the ability to implement distributed computing, in which the resources of multiple computers are combined to accomplish a single task. At the simplest level, this can be using one computer to run backing tracks and reverb while another runs a synthesizer. This requires that you manually choose which computer does what, although with audio and MIDI flowing between two synchronized computers, you have some flexibility. Dynamically distributed processing systems like Logic Node have the ability to distribute processing load automatically among computers without human intervention.

Several tools, some free, can provide these features, though they're specific to different platforms (note that these tools assume you're using a local network, such as an Ethernet connection between laptops; using the Internet poses other challenges):

  • Steinberg VST System Link; Inter-computer audio and sync (Windows/Mac): VST System Link transmits sync, transport position, and audio data between computers via standard digital audio cables (ADAT, S/PDIF, AES/EBU, and TDIF). It's a bit like having ReWire between computers: it provides the sample-accurate synchronization MIDI clock lacks plus audio data routing, and it works with as many computers as you can connect via cables. Connect the S/PDIF ins and outs of two laptop audio interfaces, for instance, plus MIDI if you want cross-machine performance of soft synths, and you're ready to go. System Link is a feature, not a separate product; Cubase and Nuendo both support System Link natively on both Mac and Windows. If you're not a Steinberg user, System Link is the most reliable cross-platform means of syncing transports between computers, and since the $50 V-STACK supports ReWire, it can be an easy way of syncing up an application like Reason or Live on two machines.

  • Wormhole; Intercomputer audio plug-in (Windows/Mac): The easiest way to route audio between applications and computers on Mac/PC is to use Wormhole, a $50 plug-in available as Windows VST and Mac VST and AU ( Figure 13.12 ). Wormhole automatically configures itself and negotiates network connections. Beyond simply routing S/PDIF digital audio, Wormhole lets you route audio as part of your insert chain, so you could route audio to another computer as an insert in a single channel strip. That makes it ideal for onstage routing applications or for manually distributing effects between computers and even platforms.

    Figure 13.12. Using Plasq's Wormhole plug-in, you can route audio between two applications on your computer or between two different computers over a network. Operation is fairly simple: add Wormhole as an insert effect on each end, make up a name for your virtual audio channel on one end, and select that channel on the other. The rest is automatic.

    Interapplication audio: Jack and Wormhole both support routing audio between applications on a computer, which is useful for applications that don't support ReWire. (Note that Pro Tools doesn't work with either tool.)


  • Jack; Intercomputer audio (Mac/Linux): The open-source, interapplication audio app Jack (www.jackit.sourceforge.net) supports audio over a network. Jack on Mac OS X (www.jackosx.com) supports the Mac's distributed devices features and audio-over-network. There's also a UDP module for the Jack audio system called jack.udp (www.alphalink.com.au/~rd/sw/jack.html) Although you could theoretically send UDP packets over the Internet, the module works best over a local network.

  • AUNetSend; Intercomputer audio (Mac): While it lacks some of the features of tools like Wormhole, Mac OS X (10.4 and later) has the ability to route audio over a network to another Mac with an Apple Audio Unit included with the OS. Insert the AUNetSend object on a track in any AudioUnit host, and you can connect to other Macs via Apple's Bonjour zero-configuration networking technology.

  • Logic Node; Distributed processing (Mac): Apple's Logic Pro supports distributed audio processing, automatically using additional Macs for processing power via a Gigabit Ethernet connection, even if those Macs don't have a copy of Logic on them. You also don't need a display on those machines, so additional Macs can supplement processing power at a gig. Effectively, you'll have a little render farm of Macs accompanying you onstage. (Apple recommends G5 computers, but many users report success using high-end G4s.)



Real World Digital Audio
Real World Digital Audio
ISBN: 0321304608
EAN: 2147483647
Year: 2006
Pages: 96
Authors: Peter Kirn

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