Regions can be stretched or shrunk in length without changing their Pitch by using the Stretch/Shrink Regions tool (shortcut “T”, for “Time stretch”).
A small adjustment to the length of a Region may not cause noticeable sound Artifacts. However, the more extreme the change in length, the more obvious the effect of processing on the sound.
To use Stretch/Shrink Regions, place your cursor on top of the region, and then Click-drag left or right. While dragging, you will see a highlighted area, which represents the new duration to which the Region will be shrunk or stretched when you release the mouse at the current position.
Time-Stretching a Region to Fit the Loop
In this tutorial, we’ve added another sound sample—this time, a synthesizer line—from freesound.org to the rhythmic passage we composed in the Creating Looped Sections chapter (search for tag “1168” in the Search Freesound tab of Ardour if you’d like to get the same sample. Import it as a new track).
After importing this synth line, we see that the length of our new Region doesn’t match the existing rhythm we’ve already created. It’s too long to be one bar and too short to be two bars.
We can correct this by using the Stretch/Shrink tool. Select the Region you wish to stretch, and drag the new length to the end of the second Bar, again assisted by the Grid settings.
When you release the mouse button, the Time Stretch Audio dialog will appear. You can experiment with different settings for the Time Stretch operation. Each will affect the sound in different ways. It’s a good idea to experiment with a few different stretch settings to find out which gives the result you’re most happy with.
Click Stretch/Shrink in the Time Stretch dialog to start the operation.
When the Time Stretch operation is complete, the region of the synthesizer line will now be exactly two Bars long, and should fit in with the rhythm we already created with the drum samples.
Continuing
This was the last chapter of the Editing Regions section. Next we go into Mixing.
Next: MIXING SESSIONS