The last time The Who performed on a nighttime talk show in America, Pete Townshend’s hair was singed and Keith Moon ended up with shrapnel in his arm. The Who will perform on “The Tonight Show With Jimmy Fallon” tomorrow, their first such appearance since their notorious performance on “The Smothers Brothers Comedy Hour” in 1967. During that show, Moon packed explosives in his drum kit, but he put several times the amount he usually did. It went off as Townshend was destroying his guitar during the finale of “My Generation.”