- Joni Mitchell. Manager convinced her a better choice would be to appear on Dick Cavett's TV show.
- John Lennon. Allegedly denied entry from Canada by U.S. officials.
- Bob Dylan. Child in the hospital.
- Led Zeppelin. Booking conflict, had to play Jersey.
- Jeff Beck. Group broke up at a bad time.
- Frank Zappa. Put off by the rainy forecast.
- Jethro Tull. Quote from Ian Anderson, "I don't like hippies."
- Iron Butterfly. Couldn't get their equipment in, or helicopter transport.
- Rolling Stones. Mick was shooting "Ned Kelly" in Australia.
- The Doors. Unclear, apparently Morrison didn't like playing outdoors. Or death threats.