I was playing around with the brief clip of 'Happy' in CS Blues, to try and sync up the correct audio to the video. The common assumption has always been that 'Brown Sugar' and 'Happy' both featured visuals from the late show at the Forum (06/11/72), with audio from the first Houston show (06/25/72). I matched the Forum audio to the visuals for 'Brown Sugar' a while back:
When I tried to do the same for 'Happy', I noticed that the mouth/mic movements for both Mick and Keith just didn't fit, so I checked through the STP Exposed site to see what other shows Mick wore the same outfit at, and Albuquerque (06/15/72) seemed like a possibility. I tried the audio from that show and it fits perfectly.
Here's a link to a .rar with three versions of the clip - as it appears in CS Blues, with the Forum audio, and finally with the Albuquerque audio. Let me know what you all think.