But I did see one with an unexpected punch line - guys are bored at the opera, one opens his coat and says Hey, I have enough for everyone - some bottled beer. As they are quietly opening their beers, the soprano hits a high note and first their 2 beers shatter, then all the ones still in the one guy's coat.
Then the guy in front of them says Fellows, next time you're at the opera... and he has a CAN of beer.

I thought it was funny...