Umphrey's McGee
The best band you've never heard of. Are hardly a "jam band" because they put every other band in the field to shame with their ridiculous musicianship. Consists of six accomplished musicians, half of which have college degrees in music. Songs are a mixture of technical, tightly composed music (featuring odd time signatures, unexpected key changes, and brilliant melodies), excellent lyricism, and UM's hilarious sense of humor, puncutated by the amazing guitar playing of Brendan Bayliss and Jake Cinninger and drumming of Kris Myers. Definitely music for musicians, but can be enjoyed by all.
Too bad bands like Umphrey's McGee, Medeski Martin and Wood, and Bela Fleck are lumped into the jam band genre.
Umphrey's McGee
The most mind-fucking band of all time. T'is the voice of god bellowing unto thee.
Jim had utter nirvana after experiencing Umphrey's Mcgee live.