the 'Montreux Music' site (www.montreuxmusic.com/crbst_204.html) claims Yes played on the 24th and 25th, but Peter Banks's diary only records a gig on the 25th. The diary also records that on the night of the 24th, Yes were en route to Montreux and didn't arrive until 11 pm, which makes an April 24 gig unlikely.