Apple Logic Pro 9 - Manual (Page 877)

Sustain Pedal Symbols in the Part Box
These two symbols are the only score symbols—apart from notes—that directly represent
MIDI events (MIDI controller #64, sustain pedal on and off ), and thus affect MIDI playback.
Logic Pro intelligently inserts the on or off version of the symbol, depending on the status
of the type that preceded it. (A sustain off always follows a sustain on, and vice versa.)
Clef Objects in the Part Box
The clefs in the Part box are generally intended for clef changes in the middle of a part,
for a short section of the music; for example, cello or bassoon parts, when the part changes
to a higher register. Inserted clefs change the score display, starting at the precise insert
position (which can even be in the middle of a bar).
Note: You shouldn’t use the Part box clefs to change the clef of a whole MIDI region. In
this situation, choose an appropriate staff style for the region. See
Working with Staff
Styles .
877 Chapter 31 Working with Notation