Time stretch using flex markers

In the Tracks area, you edit the timing of audio material using flex markers. After adding flex markers to an audio region, you use them to time stretch—compress or expand—the audio material. The boundaries within which this is done are determined by the preceding and following flex markers, or the region start and end positions if there are no preceding and following flex markers.

You can also use transients in other audio regions as reference points, when dragging a flex marker in an audio region.

Flex Time is also available in the Audio Track Editor, when Show Advanced Tools is selected in the Advanced preferences pane.

Time stretch audio using a flex marker

Choose a Flex Time algorithm for the track.
Add a flex marker by doing one of the following:
- Place the pointer over or beside a transient marker in the upper half of the waveform body (note how the pointer changes), then click.
  A flex marker is added on top of the transient marker.
- Place the pointer in the upper half of the waveform body where there is no transient marker (note how the pointer changes), then click.
  A flex marker is added at the clicked position.
Do one of the following:
- Drag the flex marker to the left.
  The audio material is time compressed up to the preceding flex marker, the preceding tempo marker, or the region start position. The audio material is time expanded up to the following flex marker or the following tempo marker (which can also be the region end position).
  If you move the flex marker to the left and it crosses a previous flex marker, the previous flex marker jumps back to the previous transient marker. This allows you to extend the Flex Time editing range to the left. The same behavior occurs if a flex marker crosses a tempo marker.
- Drag the flex marker to the right.
  The audio material is time expanded up to the preceding flex marker, the preceding tempo marker, or the region start position. The audio material is time compressed up to the following flex marker or the following tempo marker (which can also be the region end position).
  If you move the flex marker to the right and it crosses a following flex marker, the following flex marker jumps forward to the next transient marker. This allows you to extend the Flex Time editing range to the right. The same behavior occurs if a flex marker crosses a tempo marker.

Snap a flex marker to a transient in another region

Click-hold the flex marker, then drag the pointer up or down over an adjacent track.
A yellow guideline appears in the audio region on the adjacent track as you move from transient to transient.
Release the mouse button to snap the flex marker to the highlighted transient marker.

Add multiple flex markers to an audio region

Do one of the following:

Place the pointer over or beside a transient marker in the lower half of the waveform body (note how the pointer changes), then click.
Three flex markers are added: on the transient marker, on the previous transient marker, and on the following transient marker.
Place the pointer in the lower half of the waveform body where there is no transient marker (note how the pointer changes), then click.
Three flex markers are added: at the clicked position, on the previous transient marker, and on the following transient marker.