The shooting script called for Peter Frampton's character to kill Steven Tyler's, but when it came time to film this scene, Aerosmith threatened to walk out. "There's no f***ing way that Steven is gonna get directly offed by Frampton," commented Joe Perry. "It's gotta be an accident, the way it was in the original script we f***ing agreed to." They finally agreed to a compromise, with Tyler's character being accidentally pushed to his death by Sandy Farina.
Aerosmith was the second choice to play the Future Villain Band. KISS was approached first, but turned down the role fearing it would hurt their image. They instead opted to star in KISS Meets the Phantom of the Park (1978).
The film was adapted as a comic book, which was intended to be released as Marvel Super Special #7. For reasons which were never officially disclosed, the book was never issued in the USA. The comic was, however, released in France, the Netherlands and Germany (with text in the respective language of each country), but copies of these releases are scarce.
No, none of The Beatles were involved in the production, other than being given songwriting credit. However, George Martin, The Beatles producer, did produce and arrange the music for the movie. It has long been rumored that Paul and Linda McCartney and George Harrison appear in the celebrity line up at the finale, but this is not true.