Editing : Editing Clips and Selections : Trimming Clips : Trim to Selection Command

Trim to Selection Command
The Trim to Selection command removes data before and after a clip or MIDI note selection, leaving only the selection. This command lets you quickly remove all data in a clip (and in some instances the entire track) except for the current selection.
To trim unwanted data from a clip or note:
1 With the Selector tool, select a portion of a clip or note (or a range of notes).
2 Choose Edit > Trim Clip > To Selection to remove material outside of the selection.