rec.music.gdead - join
A group for (Grateful) Dead-heads.
Low activity, 1404 subscribers, Usenet

alt.music.dave-matthews - join
The Dave Matthews Band.
Low activity, 269 subscribers, Usenet

Trey Anastasio - join
The Trey Anastasio Google Group (TAGG) is a place where phans can meet to discuss and celebrate the ongoing expansion of his music and all the joy that comes with it. This is a public forum. Anyone can join and contribute. No BS, just Trey
Low activity, 341 members, moderated, restricted