Famous (kind of) for the ripoff Led Zeppelin made of them for Stairway to Heaven, Spirit is a Los Angeles psychedelic band formed in 1967. Their members are Randy California (which was a pupil of Jimi Hendrix. In fact, he gave him the artistic name California. His real name is Randy Wolfe) on guitar, Ed Cassidy (California's Stepfather) on drums, Jay Ferguson on voice, John Locke (yes, as the philosopher) on keyboars and Mark Andes on bass. They were considered the most important Los Angeles band of their time, only topped by The Doors. They released lots of albums with different members, but their most important are the first four: Spirit (1968), The Family That Plays Together (1968), Clear (1969) and Twelve Dreams of Dr Sardonicus (1970), because these four were recorded with the original line up. Of course there are great songs after those, but the escence of the band is in those four. Check them out. And here is the song Led Zeppelin ripped off for Stairway to Heaven: