Apple Logic Pro X - Manual (Page 451)

Chapter 15 Advanced edit features 451
Change the start or end point of an existing selection
Do one of the following:
m Shift-click in the waveform display to move the start or end point.
m Shift-click-drag the start or end point of the selected area in the waveform display.
Using either method, the proximity of your click—to the start or end of the selected area—
determines whether you change the start or end point boundary. The closest one wins.
Tip: If you hold down Option-Shift, the more distant selection boundary is changed (rather than
the nearer).
Move the selected area
m Option-click in the waveform display (the pointer turns into a two-headed arrow), then drag to
move the whole selection, without changing its length.