Ironically, the problem here is the same as it was for those who began the feminist movement. The roles society has given us, and the role we'd choose aren't always compatible. Many men are perfectly happy to play that role, much as some women were perfectly happy playing the role of housewives with little to no say in anything. Some are not, but we feel pressured by societal norms to fill those roles, even at the cost of our happiness.

Your example is actually a wonderful illustration of this Hyz. The guy wanted to play classical music, most likely because he enjoyed it. If I were one of the friends sitting there watching him, I certainly wouldn't have thought classical music was gay, nor would I have assumed my friend was gay for playing it, however I'd be hessitant to clap for him, because the guy next to me might think I'm gay for liking his performace. It's likely several other people in the room are thinking these same thoughts. So when one guy fills the role he's been assigned by laughing at the kid breaking away from the norm, we quickly join in, fill the role and laugh with him, maybe so we don't appear to be abnormal as well, maybe just to show everybody else that we're filling our roles as we're expected to. See, I'M definitely not gay, I'm LAUGHING at the guy playing classical music, I totally don't like that stuff! I'm a man!

It generally is the men who opress men, because being the opressor is a part of the role society has given us. It's alot like slaves being given the duty of keeping the other slaves in line, and it is one vicious cycle, because some of us have grown so accustomed to that role, that we like it, and would never oppose it, we'd even defend it against those who would. We forged our own chains, and we've worn them for so long, we no longer realize their function, and blindly continue to forge them, and place them on others, because that is the duty of those who wear the chains.

Though I can see the chains, and I'm well aware of their function, unfortuantely I'm among those happy to wear them. I like filling my role in society. So do others. As long as this is the case, unfortunately it is unlikely that societal role of men will change, and it will continue to enforce itself. Interestngly, I can only really see the cycle being broken by those not bound to it, women. Actually that doesn't seem to be too far off from my own observations, most guys who play classical music, or do other things that aren't considered part of the man's role without giving a damn what other guys think about it, do so because they're with a girl who appreciates that kind of thing, and gives them the support they want, but don't get from male friends.

Ironic then, that one of the many duties of the role, is to act as though we enjoy playing it, so those capable of freeing us from the chains never realize we want to be freed. Funny little world, ain't it?