When viewing or playing a score in the mobile app, the icon showing three sliders in the lower right will take you the Part Mixer.
- The horizontal sliders allow you to independently adjust the volume of the different instruments in a score.
- The eye icon allows you to selectively hide and show instruments from the score, enabling you to view only one part at a time if you wish to do so.
- The speaker icon with an x next to it allows you mute (turn off the playback of) individual instruments in the score. The Metronome track (at the top of the Mixer) is muted by default, but you can unmute it.
When done, tap the < icon in the top left to go back to the score.