Currently in playlist mode you have two options under the playlist name: "Solo" and "Up Arrow". When comping vocals it is very common to track a bunch of takes and make main vocals, double vocals, and quad vocals. The same could be said for comping guitar tracks or anything that needs doubles or quads. If you look on the left, those two buttons leave enough real-estate for possibly 5 more buttons. The buttons I would request would be "D" for double, "Q1" for quad 1, "Q2" for quad 2, "Q3" for quad 3, and "Q4" for quad 4. When you press "D", it will move that audio file that is highlighted to a "Double Track" that exists above or below the main track. When you press "Q1-4", it will move that audio file that is highlighted to a mono "Quad Track" (you would have 4 mono quad tracks open to choose from) that exists above or below the main track. Those buttons would be greyed out unless you have an audio track that is activated as a "Comp Track". Basically you couldn't comp doubles unless you have already created and activated an audio track for this specific purpose. Currently the "up arrow" only moves the waveform to the main track, everything else needs to be copy and pasted. If you have 20 or more tracks to sift through, you end up doing a lot of scrolling up and down just to copy and paste doubles and quads. Having "D" and "Q1-4" buttons would eliminate this scrolling and make the comping workflow more efficient.
Idea No. 734