Your story about the singer with the mask reminded me of seeing a fairly obscure Irish band called Whipping Boy. The singer came out wearing a big mask of some sort, I recall something like a burlap sack. He ripped it off halfway through the opening song to punctuate a transition, which was a surprisingly effective bit of showmanship. They were brilliant though. I remember a bicycle being used as a prop in the last song too. It was a long time ago, but I remember him lying on the ground idly peddling the bike, which was upside down. The song was about mental illness I think.
The Whipping Boy thing in turn reminds me of seeing Gang Of Four and the singer 'playing' a microwave oven during (the brilliant) He'd Send In The Army.
The 'shocking' thing about The Residents singer taking his big mask off was that they never revealed their faces or identities (or at least still hadn't at that point). But alas, in this case it merely uncovered another layer of disguise.
My friend describing that moment, underlined by his dramatic enacting of the arm movements and screeching noises, is very memorable for me in that as a result I had one of the most prolonged outbursts of uncontrollable hysterical laughter I've ever had, leaving me in such a weakened breathless state that he and the others present became quite concerned.
It was nearly matched a few years ago when I watched a Mission Impossible film on TV, in which Tom Cruise scribbles a face on his hand, essentially looking like 🙂 and asks Jeremy Renner to ID it, to which Renner immediately gives him a name and rattles off a detailed bio and how dangerous the guy is. This time it was my partner who was at first exasperated then quite worried about my welfare after I laughed myself near comatose for almost 15 minutes.
Anyway, gigs.