Apple Motion 3 - Manual (Page 360)

360 Chapter 4 Using the Timeline
To select a range of frames:
m Command-Option-drag in the Timeline.
A light blue band appears over the selected frames.
To expand or contract a region:
m Position the pointer at either edge of a region to modify its end point. Click to the right
to make it longer or to the left to make it shorter.
Selected regions ordinarily apply to all tracks in your Timeline. However, sometimes you
only want to select one or more tracks. This allows you to make complex selections
across multiple layers and tracks.
To move a region:
m Position the pointer over the region, then drag to move the region.
To deselect tracks from a selection range:
m Command-click the track you want to deselect.