Relatively crude all-encompassing term for a group of bands who are musically quite disparate. Current jam band successes include such unique groups as Phish (closer to being straight rock than anything), String Cheese Incident (
electric-grass or "acid grass"),
Yonder Mountain String Band (more traditional bluegrass), Umphrey's McGee (prog-rock and jazz influences), Widespread Panic (Southern-ish rock),
Blues Traveler (blues and power rock), Medeski Martin and Wood (jazz), etc. The originators of the phenomenon were the Grateful Dead, and Dead successors such as the Other Ones, Ratdog, and Phil Lesh & Friends carry the mantle of the Dead legacy today. The term "jam band" is of course rooted in the fact that all of these bands "jam," or improvise for long periods of time during their shows. Other characteristics of "jam band" status include dedicated traveling fan bases, close rapport with such fans, long sets at shows, etc.