Most questions on this site is about recording music. And not only are then question about how to best record an acoustic guitar on topic on several sites, somebody who records a band will want to know why that fourth string on a guitar buzzes, how to tune drums so they sounds better and where to buy a good piano stool that doesn't squeek.
There is no sharp distinction between the musicianship of a guitar hero and the musicianship of a sound engineer. In Audio Recording and production, all this knowledge is needed. When recording a band, you need to fuse the knowledge of singing, playing various instruments and how to best record them into one indistinguishable whole.
There is already a proposal for Musical Practice and Performance. I think that it should be extended to include recording. The main reason it doesn't already do this is because audio.SE already exists. The users here should all commit to it, and we could then move these questions there.
There is a similar discussion on guitars.SE, and seeding a new music site with questions from audio.SE and guitars.SE would make for a healthy start.
UPDATE: music.SE is here now. This is therefore now more a question of if we should migrate the music recording questions or not.