9.9. ReWire

ReWire is a music-synchronization technology that lets music programs running on the same machine control each other . As its developer, Propellerhead Software, puts it, ReWire is an invisible cable that streams audio from one computer program into another (Figure 9-10).

How is this useful? Because not all music programs have every feature in the world. The software called Reason (also from Propellerhead), for example, is wildly popular among Mac musicians who've tried it. Reason beautifully simulates the controls ”and the sounds ”of a sophisticated real-world synthesizer, complete with stacks of recording-studio processing modules. It can't, however, record live audio (like singing ), and it doesn't offer looping.

But GarageBand does, of course. Thanks to ReWire, you can create a little musical ecosystem of programs that work well together.

Suppose, for example, that you have Reason (or you've downloaded the free demo version just to fool around with it). All you have to do is:

• Open GarageBand.

• Then open Reason.

You've just established GarageBand as the master , the software that will control all other ReWire-compatible programs (the slaves). If you now click Play in GarageBand, you'll hear whatever music is in Reason begin playing in perfect sync. Change the tempo in GarageBand, and Reason's tempo changes too. The volume slider, Cycle controls, time display, and other GarageBand controls work, too, controlling both programs simultaneously . (To make the slave program louder or quieter relative to GarageBand, go into that program and adjust the output volume manually.)

In short, the slave program (Reason, in this example) behaves exactly as though it's a set of tracks right in GarageBand (Figure 9-10).

---

Tip: One chief advantage of using Reason (or another ReWire program) as a slave backup band for GarageBand is that it doesn't require nearly as much memory and processor horsepower as GarageBand. You can build up a number of tracks in Reason, then use GarageBand only for recording a few live-instrument tracks, like voice and acoustic guitar.

---

Figure 9-10. Add vocal tracks, throw in some loops , record some MIDI keyboard performances , and otherwise use GarageBand as you normally would. The only difference is that you've got a whole orchestra of synthesizers ”in the form of Reason or whatever ReWire-compatible programs are running ”playing along.
When your work is finished, you can use the File Export to iTunes command as usual. GarageBand will incorporate both its own tracks and those from Reason into the finished product.

You can read a lot more about ReWire at www. propellerheads .se. There you'll find not only a step-by-step mini-tutorial, but also a list of pro music programs that work with ReWire. They include Digital Performer (Mark of the Unicorn), Live (Ableton), Pro Tools (Digidesign), Logic (Apple), Cubase (Steinberg), and others.