Collapsing Mixer Sections

Mixer sections can be collapsed in order to save space on the screen. This can be useful if the song contains a large number of tracks. Sections can be collapsed, and expanded again, by leftclicking the small button in the top-right corner of the section. While collapsed only the section's name is visible, all controls are hidden.

More powerful options are available if you Ctrl-Click the button:

You can collapse/expand all same color tracks by pressing the Alt key while clicking the button.