[Graphic of the selector, with selected and unselected states]
The Selector lets you select LoopTracks to to be controlled by the Gang.
To select LoopTrack(s), drag from the Selector area. Whatever LoopTracks selectors you drag over will be selected.
To select a range of LoopTracks, drag straight down or up over selectors, or skip out to the left to jump over LoopTracks. To select just one LoopTrack, click and release.
Unselecting LoopTrack(s) works the same way, using the right button.