Tracks
A track is a column in the Perform grid. Each track drives one group of fixtures and plays one clip at a time. Tracks are layered like layers in an image editor: the lowest is at the bottom, and each one above is blended onto the ones below it.
Add and arrange tracks
+ Track (⌘T) adds a track. Click a track's name to select it; its settings open in the inspector (Show inspector in the header if it's hidden). There you set its name, the group it plays on, its color and its effects. Duplicate (⌘D) copies a track with its clips and effects. Groups are made in Setup. Add a track for each group, in a new show's setup checklist, adds a track for every group no track plays on yet, each named after its group, as one undo step.
Scenes, at the head of the scene column, is the master track. Click it (or Scenes at the top of the arranger) to see the show's settings in the inspector: when launches start, the fade between clips, the tempo source, deck info and the show's variables. The master track is always there; it can't be moved, copied or deleted.
Tracks and scenes can have a color, shown on the grid and the tablet.
Blend mode and fader
Each track has a blend mode (the menu showing Normal by default) and a fader in the mixer at the bottom. The mode says how this track combines with the tracks below it; see Blend modes. The fader says how much of it you get; see Faders, mute and solo.
Mute, solo and the rest
M mutes a track while it keeps playing, so it comes back in time. S solos it. These are live controls and aren't undoable.
Ignore scene launch on a track leaves its playing and queued clips alone when a scene launches. Direct clip launches and stop buttons still work. Use it for a background wash that should keep going through the whole set.
Track effects
A track's effects apply to every clip on it; click the track's name to edit them. See Effects.