Grateful Dead: Truckin'
[more free media from this same concert @ the Internet Archive]
Truckin' may have been one of the band's lasting memes: the image on the cover of the band epitomizes the idea: a "cat" moving on- on foot. Originally released on their "American Beauty" album in 1970, the song has been accorded the status of "national treasure" by the Library of Congress.
For more details about the dead, check out one of the best Dead-related online links I have ever seen: http://deadessays.blogspot.com/