Apple Logic Pro 9 - Manual (Page 712)

Protecting the Position of Events
There are situations when you will want to protect certain events from being moved. For
example, several note events may be used to trigger footstep samples that match an
actor walking down a corridor, in a video soundtrack.
You have already created the music for this scene, but have been asked to increase the
tempo to match several cuts of different camera angles in the corridor. Obviously, a
change in the project tempo will move the events, resulting in out-of-sync footsteps.
Fortunately, Logic Pro has a feature that preserves the absolute time position of events.
To protect the position of one or more selected events
µ
Choose Functions > Lock SMPTE Position (or use the corresponding key command).
This ensures that events that fall at a particular absolute time position—1 hour, 3 minutes,
15 seconds, 12 frames, for example—remain at this position when tempo changes are
made.
To unprotect the position of one or more events
µ
Choose Functions > Unlock SMPTE Position (or use the corresponding key command).
Editing Events
The list area features several columns: Position, Status, Ch(annel), Num(ber), Val(ue), and
Length/Info. These columns display all details of all event types. In most cases, you can
directly edit the data displayed (with the exception of the Status column, which merely
indicates the event type).
Not all columns are used for every type of event. For example, system exclusive messages
are not MIDI-channel specific, so the Ch(annel) column is unused. Channel and polyphonic
pressure messages have no length, so the Length/Info column is left blank.
712 Chapter 25 Editing MIDI Events in the Event List