The master volume slider controls the output level of the entire application. To show or hide the master volume control bar, select Master Volume from the View menu, or press Shift+V. Note that the slider supports automation, which means you can program Mixere to fade in or out by itself, while you do other tasks. This is useful when Mixere is combined with other audio applications. For example, while Mixere fades itself out, you could manually fade in another application.