Select Project 18
Nope – I won’t have 18 projects open. Common wisdom is that having more than one project open at a time can lead to project corruption.
This could be a holdover from the early versions of Logic where projects were called “songs”, and people using Logic for playback in peformances would have many songs open, strictly for playback.
The current world has MainStage for playback purposes. A far better tool for backing tracks or, possibly, programmatic audio.
There is no documentation in user manuals for Logic 7, 8, 9, or 10.