Grateful Dead

The Grateful Dead was an American rock band formed in 1965 in the San Francisco Bay Area. The band was known for its unique and eclectic style, which fused elements of rock, folk, bluegrass, blues, reggae, country, jazz, psychedelia, and space rock — and for live performances of long musical improvisation.

http://en.wikipedia.org/wiki/Grateful_dead
http://www.dead.net/