Caught Between The Twisted Stars 4CD box:
Disc 4: Illuminations Of Atonality
April 14-16 or 21-23 or 28-30, 1967
The Gymnasium, New York City, New York
06 Guess I'm Falling In Love
silver CD>Mac G4 desktop>Peak>xACT>flac
The lineage given above is from the original seed of this disc which I estimate to have been sometime in early 2005. From the obvious vinyl noise I think it's safe to assume that the recording for the CD was sourced from the (excellent) vinyl bootleg, 'And So On'.
Cale said in some interviews he owns the tape of the entire Gymnasium show, including Walk It As You Talk It with a really good guitar sound. There's an 'old' recording of Guess I'm Falling In Love, broadcasted on WPIX FM by John Cale on June 3, 1979, and available on some bootlegs like And So On LP or Everything You've Ever Heard... 3LP box set. This version sounds clearly different (seems without drums) from the Peel Slowly And See box set version and has some lyrics differences (the box set version begins with "I got fever..." while the 'old' version begins with "I got MY fever..."). On the WPIX tape where Cale plays the 'old' version he clearly says that it is from a tape he stumbled across. He definitely says "Gymnasium, April 1967"