The Track Titlebar
Each track displayed in the Graphic Editor has a corresponding titlebar. A tracks titlebar contains a series of buttons and pop-up menus allowing for a number of operations relevant to that track, including Output assignments, Data Type display, Record, Mute, Solo, Loop, the resizing of the tracks vertical display (only when displaying multiple tracks), and the ability to change the display to another track Number.
When displaying more than one track at a time, titlebars of any inactive
tracks appear differently. You can make a track active by clicking on its titlebar
or anywhere within its display area (Shift-click to activate multiple tracks at once).