In 1976, Queen's album "A Day At The Races" opened up with Brian May's "Tie Your Mother Down".  The intro to the song described below, is only found on the album version.
 
"The song is preceded, first, by a multi-tracked guitar part reminiscent of the song "White Man," then by a one-minute instrumental intro using a Shepard tone harmonium figure, which is actually a reprise of the ending of "Teo Torriatte": this was intended to create a "circle" in the album. The ascending scale was created by recording a descending scale on a harmonium and playing it backwards for the record." (Quote from Wikipedia.)
 
I would be willing to bet that the Shepard tone intro was Brian's idea, who always developed the most massive guitar orchestrations.