I didn't know how I would react when I saw Morrissey live. Hadn't thought about whether I'd sing along or not. However when the band busted out the first few bars of Panic, and 5000* people started singing, I couldn't help myself. It wasn't something I was consciously doing - just the euphoria of the moment.
Sorry to anyone had to listen to me sing most of the setlist. I don't exactly have a booming voice or anything, so I doubt I ruined it for those around me. In any case, they looked just as caught up in the occassion as I was.
As for other people singing badly (off-key, annoying voices, really f***ing loud, etc), I could only hear the crowd singing, not one particular person. Mind, I was so focussed on Morrissey that it even if William Hung was standing next to me with his own mic I doubt it would have bothered me.
To answer you question pandora_cocteau, I think it adds real energy to a concert when the crowd sings. Not just Morrissey gigs, any band.
(*correction on the number: 4900, I now know some of you were miming!
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