It's one of the most famous lost footage reels in Brit-rock history: David Bowie's glammed-out take of "Gean Jenie" on the show in 1973. It was a performance that turned a generation of Brits into glam fans, and it was aired only once. It was then accidently deleted by the BBC, which had resigned itself to never finding the footage, occasionally putting out calls to people who may have shot it using a Super 8 pointed at their TV.
It turns out, an original cut of the footage just turned up: Cameraman John Henshall, who shot the performance, just found a copy of the performance in his professional reel, as he kept it because he knew it was great. The footage was recently aired at a fest, and it's sure to end up on a DVD soon. Read more over here.