Apple Logic Pro 9 - Manual (Page 1050)

Transposition events only affect MIDI events already in your project. They do not affect
MIDI events that you create or record after editing the transposition events.
MIDI events will only be transposed if the No Transpose checkbox is unselected in the
respective Track Parameter boxes.
Apple Loops
Apple Loops can contain information about the key they are in, and can be transposed
automatically. Regular audio regions (audio regions that are not Apple Loops) are not
affected, nor are Apple Loops that do not have a key definition (drum loops, for example).
For full details, see
Using the Chord Track with Apple Loops .
Creating and Editing Transposition and Chord Events
Creating and editing transposition events works similar to standard MIDI events.
To create a transposition event in the Transposition track
Do one of the following:
µ
Click a position in the Transposition track with the Pencil tool.
µ
Hold Control-Option-Command, click a position in the Transposition track, enter a
transposition value in the text field, then press Return.
A transposition event of the typed value is created at the clicked position.
To change the transposition value of a transposition event
µ
Drag the event vertically.
1050 Chapter 35 Editing Transposition with the Chord and Transposition Tracks