FWIW, we've found that passion for music is a huge positive signal that somebody will be successful as a developer within our product line (small portion of a large company - don't know if that signal holds true outside my group).

Obviously, we don't limit candidates to those who are also musicians. Heck, we don't even tend to ask about it in interviews. But, it serves as a general "we probably did ok with this hire" shortly after on-boarding.