Mute. This button, marked M, silences the track. It can also be controlled by automation. During a section which is muted by the automation in the Timeline, the Mute button will be depressed. You can release it to override the automation.

If the track is assigned to a Subgroup, it will be silent if the Mute button is pressed in either the Subgroup or the Mixer (or both).

Solo. This button, marked S, will silence all the other tracks, so that you hear only the solo track. If two or more tracks have the Solo button depressed, you will hear all the Solo tracks but no others.

Combinations of Mute and Solo This diagram shows what happens to a track when various Mute and Solo buttons are on or off.