This feature allows you to change the tempo of the song without affecting the pitch (e.g. so it doesn’t sound like the chipmunks when you speed up the song).
To activate Key Lock, click on the music note icon () right next to the speed slider.
Note: Key Lock is only supported on the following devices:
- iPad 2 or better
- iPad mini
- iPhone 4S or better
- iPod touch 5th gen. or better
- Google Nexus