One of the normal set-ups in Garageband is a MIDI keyboard hooked up to your mac and this MIDI keyboard triggers the built in instruments.
Works great, and give you all kinds of cool editing choices after you have recorded your music.
Sometimes your controller keyboard has awesome patches in it and you want to record these to Garageband. Not a problem... simply hook up the outputs of your keyboard and input these into your mac and record to a REAL AUDIO track in Garageband.
What I like to do is ARM 2 TRACKS in Garageband and record a MIDI track simultaneously with your audio track!!! This offers up some cool possibilities!! It will allow you to layer up your real track with an instrument tract... or create a cool duplicate track to vary your song structure... etc...etc...
Give it a try!
hear my latest GB music...
Hope all you GB users are creating great music!