This extremely rare massacre took place in 1974 while The Who's Pete Townshend was rather long-windedly waxing poetic about the positive attributes of Rock Music. Interviewer Melvyn Bragg, usually possessing a keen eye and ear for journalistic detail, swears to this day that this mishap never occurred. Well, as much as I admire Bragg as a journalist, I must respectfully disagree here, as the footage clearly tells the tale.
As for Townshend, he was so inebriated during this interview that he didn't realize what had happened until The Who started assessing footage to be used in The Kids Are Alright almost three years later (The Who, perhaps mercifully, opted not to use this part of the interview for the film).
Click on the image to view the footage. Enjoy.