September 15, 1967
The Smothers Brothers Comedy Hour started out as only a slightly "hip" version of the typical comedy-variety show of its era, but rapidly evolved into a show that extended the boundaries of what was considered permissible in television satire
The performance by The Who in 1967 was another defining moment in the series; as the group often did during that period, The Who destroyed their instruments at the conclusion of their performance of "My Generation", with the usual addition of mild explosives for light pyrotechnic effect. The piece would end with guitarist Pete Townshend grabbing Tommy's guitar and smashing it.
On the Smothers Brothers show that night, a small amount of explosive was put into the small cannon that Keith Moon kept in his bass drum. But it didn't go off during the rehearsal. Unbeknownst to Moon, a stage hand had added another explosive before the taping, and later Moon added another charge so that now there were three explosive charges in the cannon instead of one.
When Moon detonated it, the explosion was so intense that a piece of cymbal shrapnel cut into Moon's arm; Moon is heard moaning in pain toward the end of the piece. Townshend, who had been in front of Moon's drums at the time, had his hair singed by the blast; he is seen putting out sparks in his hair before finishing the sketch with a visibly shocked Tommy Smothers.
Allegedly, the blast contributed heavily to Townshend's long-term hearing loss.