When Show Advanced Tools is selected in the Advanced preferences pane, you can you can transpose (change the playback pitch of) MIDI regions and Apple Loops in a project over time using the Transposition track. The Transposition track contains transposition points for pitch changes (transposition events). The project transposes at the position of the transposition point, and remains at the new value until the next transposition point.
Transposition affects both audio and software instrument Apple Loops (except drum loops, and other Apple Loops with no defined key) as well as MIDI regions. Audio regions other than audio Apple Loops are not transposed.
The zero position of the Transposition track is determined by the current key signature in the Signature track. If the key signature changes during a project, the zero position of the Transposition track changes accordingly.
Transposition works nondestructively, and transposed MIDI notes return to their original values when the Transposition value is reset to zero (0). For example, starting with a C3 note event in a MIDI region, adding a transposition point with a value of +2 changes the note event to a D3. If you change the transposition point to a different value, the note is transposed by the corresponding amount. When you change the transposition point so that the transposition value = 0, the note returns to a C3. Similarly, if you copy a region to different parts of the project with different transposition values, the notes in the region change by the corresponding amount.
When you add or edit a transposition point, only existing MIDI events in a project are transposed. MIDI events recorded or created afterward are not affected.
If the No Transpose checkbox is selected in the Track inspector, MIDI events (including instrument Apple Loops) are not transposed for that track.
Show the Transposition track
Do one of the following:
Choose Track > Global Tracks > Show Global Tracks, or use the Show/Hide Global Tracks key command (G).
Click the Global Tracks button . In the Tracks area, the Global Tracks button appears above the track headers; in the editors, it appears on the left side of the editor.
Control-click anywhere in the global tracks header area, then select Show Transposition in the dialog that appears.