GarageBand: Set the Song's Key Before Recording MIDI

GarageBand creates new songs with a default key of C. If you decide to change the key later, all of your MIDI notes will be transposed to the new key. To avoid having to transpose your software instruments, be sure to set the song's key before recording anything.

To change the song's key:

1. Click the Track Info button to open the Track Info window.
   
2. From the pop-up menu at the top of the window, choose Master Track.
   
3. From the Key pop-up menu, choose a new key.

If you've already recorded a track in the wrong key, use the Transpose slider in the Track Editor to adjust the pitch of the region.