Apple Logic Pro 8 - Manual (Page 471)

Chapter 20 Editing MIDI Events in the Transform Window 471
Reverse Pitch
Inverts the pitch of all note events.
Change the Flip operation value to set a pivot point note number, around which note
event pitches will be reversed.
Transposition
Transposes all note events.
 Change the Add operation value to the desired amount (in semitone steps).
 You can achieve downward transpositions by setting a negative value in this field.