Back in my student days I used to attend a pub that had it on every Tuesday night. My friend would perform, I just went for the cheap barmaid and the attractive beer with the big tits - or something like that. Anyway, one fella used to turn up week in, week out dressed in the full Elvis, the Vegas years. He did The Wonder of You every time without fail - and to be fair he was quite good. Then, one week, he tried a different song and was utterly terrible. I felt quite sad for him.
I did karaoke once in Dubai - too pissed to remember what I sang but it was definitely a definitive performance