[Audio mixer] dialog box

The [Audio mixer] dialog box allows you to set the volume for all the tracks or each of the tracks.

Track Names
Names of all the tracks are shown. If the Master volume is set, it will be the setting for all the tracks.
Fader
Drag the fader to set volume.
[Mute] button
Sets the volume to 0 (mute).
[Solo] button
If the [Solo] button is clicked, only the track whose [Sole] button is clicked is played back and other tracks are set to mute.
[Gang] button
If one of the [Gang] buttons is clicked, the fader for the track turns into the color of the button clicked. The faders having the same color move synchronously keeping the difference in dB constant.