by Todd M. Fay

DirectMusic is software that allows composers, sound designers, and audio engineers to create digital musical content with interactive, variable, and adaptive playback properties. What does that mean? Moreover, who cares? Chances are that Joe Musician is not terribly familiar with the terms "interactive," "variable," and "adaptive" as they relate to audio production — and for good reason; musical pieces featuring these properties have yet to enter the musical mainstream. Well, we are here to change all of that

DirectMusic in Interactive Media Development (aka Computer/Video Games)

While not familiar terms in mainstream music production or motion picture post, interactive, variable, and adaptive audio playback are mainstay terms in the world of game audio production. Games, like other visual media, use audio as a means of communicating information and manipulating audience emotion. However, there are some pitfalls inherent to the medium that audio producers need to deal with, namely nonlinearity, variable environments, repetition, storage space, and processing power limitations. These potential roadblocks require unique creative and technical solutions. DirectMusic exists, in part, to assist audio producers in dealing with these unique problems.

DirectMusic is part of DirectX Audio, the aural components of a suite of software tools (or "library") collectively referred to as DirectX. Microsoft created DirectX to give programmers powerful tools to create games for Windows PCs. And they succeeded; DirectX made Windows the premier PC platform for games. DirectX Audio consists of two component parts named DirectMusic and DirectSound. At first, DirectX had only the DirectSound library. Programmers used DirectSound for basic playback of a game's audio assets. DirectMusic was introduced later on to give composers and sound designers more control over their contribution to the game. Today, the two are referred to collectively as DirectX Audio. We focus mainly on DirectMusic in this text because it is easier to work with from the perspective of a composer and sound designer and is in effect more powerful. Just understand that DirectSound came into existence before DirectMusic, and DirectMusic was built, in part, on top of DirectSound. This is already more than you need to know, so let's avoid entering into anymore details here, as there is a book on the subject (the one you're holding).

Greater Control for Audio Producers

In the early days of game development, audio producers were largely dependent upon audio programmers (software engineers) to get their sounds and music into their game, a process known as integration. DirectMusic relieves much of this dependency. Using DirectMusic Producer, an audio producer can place all of his or her waves, sequence data, sample sets, and even instructions on how audio should be played interactively, adaptively, and with variation. The sum of the audio producer's work is saved in a file called a Segment (.sgt files). A Segment is to an adaptive, interactive, and variable score as a wave and/or MIDI file is to a linear score. Because of the completeness of the information and data stored in a DirectMusic Segment, the role of the programmer in integrating is reduced significantly. Gone are the days of a project's audio programmer screwing with volume levels or triggering sounds to the wrong events. The programmer doesn't need to know how the audio gets played back; he only tells the game to play the piece of music, and whatever audio data and parameters were specified by the composer are used at playback.

This is useful for audio producers creating stand-alone music with DirectMusic. They can save all of their samples, waves, sequence data, and instructions for adaptation, variation, and interactivity (if any) in the Segment. The listener then loads the file into their DirectMusic player program, and vol — beautiful music!

There will, of course, always be some amount of information that programmers and composers must communicate to each other. Programmers must let the composer know how much memory he can use for sample, wave, and sequence data or whether he can stream wave data off of the hard disk or CD/DVD. The programmer generally needs to know how to transition from one piece of music to the next (measure, beat, marker boundaries, and so on). The programmer typically implements things like tempo changes based on game state. However, a composer (or programmer) can instead take advantage of the DirectX Audio Scripting language for greater control over these aspects of playback from the programmer. A scripting language provides the audio producer with the ability to create simple easy-to-read "programs" (known as routines) that a programmer can then run based on programmatic events. The language is designed to be simple to learn but still have a lot of flexibility and power in what it can do for audio producers. We discuss this more later.

DirectMusic for Music Production

The applications for interactive, variable, and adaptive audio, particularly music, extend beyond computer and video games. The potential for DirectMusic to alter the way we listen to digital music in our homes, cars, and anywhere else where we can smuggle a personal musical player is very exciting. Music written with interactivity, adaptability, and dynamism allows audiences to take a more active role in their listening experiences. A recording artist's next single could be a DirectMusic module that listeners can intuitively remix with, introduce new musical parts and effects to, or set to react to changes in their computing environment. It could even be made to never play back the same way twice, if listeners so chose!

Admittedly, not everyone is interested in having such an active role in music listening. Passive listeners can still enjoy enhanced musical experiences by setting their DirectMusic songs to play back according to packaged templates. "Factory settings" could provide alternate instrumentation, allowing a jazz piece to take on more of a world, rock, or hip-hop feel for instance, even switching back and forth between styles and instrument sets. Other templates could range from intelligent "concert hall" or "arena" reverberation settings using built-in effects processing to completely self-generated performances based on a loose set of criteria created from scratch with every play.

There are plenty of tools on the market that allow just about anyone with a few hundred bucks to begin creating music on his computer. The differences between your average audio editing or multitracking program and DirectMusic are the interactive, adaptive, and variable abilities that you will not find anywhere else (at least not to this degree). Remember, these kinds of soundtracks, songs, and soundscapes are for the most part unexplored territory. We assure you, the terrain in this territory is unlike any you've experienced before, either as a composer, a performer, an engineer, or a listener.

At the time of this book's publication, Microsoft wasn't promoting DirectMusic as a mainstream music production tool. DirectMusic was virtually unknown to the millions of music-producing hobbyists and professionals looking for new ways to distinguish themselves among their peers and audiences. Only a few members of a small community were using DirectMusic for audio production outside of games. Our solution to bringing interactive, adaptive, and variable music to the masses? Educate audio producers on how to use DirectMusic to create new sonic and musical experiences. The more DirectMusic songs created, the more that people can begin to experiment and appreciate these new musical experiences.

DirectMusic is the chosen platform for this neo-musical production crusade for three reasons. First, its depth. There is not, to our knowledge, any other interactive/adaptive audio solution as comprehensive as DirectMusic. Secondly, its reach. Anyone with a Windows machine and DirectX 6.1 or higher can enjoy music created for DirectMusic. Oh, and number three: It's free! We wish we could add "ease and convenience of use" to our list of reasons to love DirectMusic, but if that were the case, you would not have much use for this fine text! DirectMusic Producer (the program Microsoft gives you to create DirectMusic content) is not user-friendly production software. In all fairness to the designers at Microsoft, DirectMusic Producer (DMP) isn't commercial software, and it was never meant to be. It's a bit convoluted as an interface, and it certainly isn't pretty to look at. Add a slew of alien concepts in audio production, and you have a significant barrier to entry. Up until now, there wasn't even a book on how to get around in DMP, let alone DirectMusic. The good news is that since DMP is simply an interface for producers to work with DirectMusic, someone somewhere could build a more user-friendly program to replace DMP, without sacrificing any of DirectMusic's power. Of course, it's pure speculation as to if that may ever happen In the meantime, DMP gets the job done. Heck, we often rely on another sequencer/multitrack and editing software package for the bulk of our production work — only using DMP when we want to apply some of DirectMusic's unique functionality to our productions (dynamism, interactivity, and/or adaptability).

Without a doubt, the single biggest drawback to producing music using DirectMusic is the lack of a customizable, standardized, and widely available player program. See, DirectMusic files are special in that they cannot just be opened in Windows Media Player, Real Player, Winamp, or whatever other music player people use day in and day out. They have to be played back using a program specially written to play DirectMusic files. Truth be told, WMP, Winamp, Real Player, and their peers could support DirectMusic files, but they just don't. Maybe someday they will, but for now DirectMusic playback options are limited to launching DirectMusic Producer or writing your own player. Luckily for all of us, Mr. Todor Fay (not to be confused with Todd M. Fay!) decided to create Jones. Jones is a DirectMusic player. You can load a DirectMusic file into it and play it back. Jones is free, and you can distribute it as you see fit! So get it out to your audience so they can listen to your new musical creations! There is more on using Jones later

Excited? Good! Read this book and dig into what DirectMusic has to offer you! The wisdom in these pages and the software offer you a grand opportunity for you to distinguish your art from that of your strictly linear audio-producing peers.