You need creative or technical credits (8-ish songs) on a cd. That's not an exact quote but it's close enough. I'm not a voting member but my previous boss (40 years my senior) is.
You only need 6, but that's pretty much spot on. You basically need writing or technical credit on six songs to be a member and that can be: vocalists, conductors, songwriters, composers, engineers, producers, instrumentalists, arrangers, art directors, album notes writers, narrators, and music video artists and technicians.