The protect and unprotect functions are available only when Advanced tools and additional options is selected in the Advanced preferences pane.
There are times when you will want to protect certain steps 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. Any change to the project tempo will move the events, resulting in out-of-sync footstep samples. To circumvent this problem, Logic Pro has a feature that preserves the absolute time position of events.
The protect and unprotect functions are available only when Advanced tools and additional options is selected in the Advanced preferences pane.
Choose Functions > Lock SMPTE Position (or use the corresponding key command). Events that fall at a particular absolute time position—1 hour, 3 minutes, 15 seconds, 12 frames, for example—will remain at this position when tempo changes are made.
Choose Functions > Unlock SMPTE Position (or use the corresponding key command).