I have. Quite a few times. When I hear them I want their hand in marraige THAT SECOND... even if I've never seen their face and know nothing else about them.
I know I'm weird but... am I that weird? :p
I find this thread quite hiliarious because my friend is singing Boyz-2-Men this exact moment
Yes, I have. A girl I knew from a long time and whom I found cute, but nothing more. I heard her sang in a gospel choir (she was solist). Tore my heart in two to the point I just wanted to grab her and run away.
But actually it happened to me too for a girl that was playing flute. So it might just be that I find girls playing music quite hot - so if they're already cute in the beginning, I fall for them.