Download midiO, an Audio Unit plugin for GarageBand. This plugin allows one to drive a MIDI based synthesizer with one or more GarageBand tracks.
Changes since 1.14:
As always, comments, bug reports, feature requests etc. will be happily fielded at retroware@comcast.net.
Version 1.1, posted on 5/16/04, added support to directly drive external devices without the need of the midipatchbay program.
Version 1.11, posted on 5/18/04, fixed the GUI to work correctly with GarageBand 1.1.
Version 1.12, posted on 5/23/04, supposedly fixed stuttering problem
Version 1.13, posted on 5/24/04, fixed a bad bug in 1.12
Version 1.14, posted on 9/2/04, improved midi timing
MacMirconizer is an enhanced port of the micronizer, an open source program that allows real-time control of the Alesis Micron synthesizer.
Download it here: macMicronzier.
Thanks to mrbook for all of his hard work developing micronizer.
Soundflower is an audio device driver from Cyling74 that allows one to route audio between Mac OSX applications. The most recent Universal Binary (version 1.2) being shipped by Cycling has several bugs, one of which prevents Soundflower from being used with Ableton Live. I've developed a patch which corrects these problems.
Download it here: soundflower patch.