So much more than just the archetypal jam band, the Grateful Dead grew to become an artistic and cultural institution that existed entirely on their own terms. While the band initially came out of a psychedelic revolution in the Bay Area's musically and chemically exploratory mid-'60s, they quickly evolved from their acid rock beginnings, incorporating elements of Americana and Bakersfield country into gently majestic albums like 1970's American Beauty. Their live shows were completely separate from their studio output, based on freeform improvisation borrowed from jazz and ma...