Perform mode can be accessed by selecting a song, and then selecting this icon:
The Perform view of a song allows you to take a selfie video of yourself playing while you have the reference of the chord changes and lyrics (if available). Keep in mind no Apple Music audio, backing tracks, or metronome will play while in this view. After recording, you'll be prompted to save or delete your video. If you save the video, it will save directly to your device. The video will have no overlays, and you can share it as you'd like! We don't upload your video or save to the cloud, it all remains local on your device only.