After the success of their initial studio work, they decided to tour, with their first show being the opening act for Jimi Hendrix in 1967.
The Original (Classical) lineup consisted of Gary Brooker (piano and lead vocals), Robin Trower (guitar), Matthew Fisher (organ), David Knights (bass), B.J. Wilson (drums), and Keith Reid (lyricist), though there were many, many lineup changes before they broke up in 1977.
Point of interest: Procol Harum's "A Whiter Shade of Pale" tied with Queen's "Bohemian Rhapsody" for Best British Pop Single 1952-1977.
Dave: Yeah man.
Bill: I'll break out the Procol Harum