Excerpts from Wikipedia on Spirit
The group's first album, Spirit, was released in 1968. "Mechanical World" was released as a single (it lists the playing time merely as "very long"). The album was a substantial[weasel words] underground hit, reaching #31 and staying on the charts for over eight months. The album displayed jazz influences, as well as using elaborate string arrangements (not found on their subsequent recordings) and is the most overtly psychedelic of their albums.
They capitalized on the success of their first album with another single, "I Got A Line On You". Released in November 1968, a month before their second album, The Family That Plays Together, it became their biggest hit single, reaching #25 on the charts (#28 in Canada). The album matched its success, reaching #22. They also went on tour that year with support band Led Zeppelin, who were heavily influenced by Spirit—Led Zeppelin played an extended medley during their early 1969 shows that featured "Fresh Garbage" among other songs, Jimmy Page's use of a theremin has been attributed to his seeing Randy California use one which he had mounted to his amplifier, and it is now widely accepted that Page lifted the descending guitar figure from Spirit's instrumental "Taurus" for Led Zeppelin's signature tune "Stairway To Heaven"[1].
After the release of Clear, California was called upon again[clarification needed] to give the group a hit single. With the group producing the record on their own, they recorded a song California had written called "1984". With a title that echoed the George Orwell book of the same name, it was one of California's finest[peacock term], and it boasted an excellent production job[peacock term] (and was one of the most ferocious[clarification needed] things that Spirit would ever record).[citation needed] And it looked at first like it would be the group's biggest hit yet. Soon[when?] after being released, it raced up the charts to #69.
In retrospect, no one is sure why the single had such a brief chart life, but there are several possibilities. It is no secret that Lou Adler's alliance with Epic Records was uneasy at best, and at the time that the single was released, Adler's distribution deal with Epic came to an end. He had been eager to move distribution of the label to A&M Records, which he did as soon as the deal with Epic ended, which might have killed the commercial availability of the single (though Adler ended up giving Spirit's contract to Epic in the process). It has also been said that there was a tip sheet distributed to radio stations outlining the song's supposed political and social views, and opining that it might not be appropriate for air play. The song would finally see general release on The Best of Spirit in 1973.
In 1970, Spirit started working on what is widely considered to be their best LP, Twelve Dreams of Dr. Sardonicus. On the recommendation of Neil Young the band chose David Briggs as the producer. It was a prolific time for the group's writers and the album was finally released in late 1970. Especially memorable was Randy California's poignant "Nature's Way", which was written in an afternoon when the group was playing at the Fillmore West in San Francisco.
Epic released an early mix of "Animal Zoo" as a single, but this only made it to #97 on the charts. Like The Who's Tommy and Pink Floyd's The Dark Side of the Moon, Twelve Dreams of Dr. Sardonicus is critically regarded as a landmark of art rock, with a tapestry of literary themes about the fragility of life and the complexity of the human experience, illustrated by recurring lyric "life has just begun", and continued the group's pioneering exploration of environmental issues in their lyrics (cf. "Fresh Garbage"). The album is also notable for its inventive production and the use of a modular Moog synthesizer.