According to David Watkinson's "Perpetual Change" (2001) Yes book, the following day (Saturday 11 April 1970) Yes went to BBC TV studios in London to record a television appearance on "Not Only... But Also" (Peter Cook and Dudley Moore's the comedy sketch show). Chris Squire mentions it on the bonus interview on The Syn live DVD (2006). It is unclear if the recording still exists - other episodes from the series have been released on video (called "The Best Of What's Left Of Not Only But Also" suggesting that whatever is not included on that 90-minute VHS has been lost, who knows Yes may even be on it, but I doubt it). It is also unclear whether the band played or starred in a sketch, or both! Would be great to ask Chris Squire!