haha. bob, your threads are the ones that get me in the most trouble. they start out so sincere and end up with all kinds of answers. first i must start out sincerely answering your question - as in the past i have had some questions like this too, but too scared to ask.
i have a little nephew who is a joy to my heart, but he does not fit the macho man kid. he is skinny, tall, and really fun to be with. he likes music, dance, and is currently learning celtic dancing. he's really good. he's very sensitive. and, he's extremely smart (brag brag) kids tend to tease guys like this because they want them to fit the mold of what they think a guy should do or be like.
over time, i have realized that society does place a huge strain on guys (and girls) to be or do exact behaviors whereas a range of things may be more comfortable to one than another. ps. my nephew happens not to be gay, but many musicians and dancers probably are as skeptotamus said.
anyway, if you happen upon a gay teacher - they will probably give you some of the best instruction in piano and you will not be wondering or fearing them. i never ask, and really don't care. just because i have a different belief system doesn't mean that i wouldn't appreciate what they have to teach. if they add crossing of legs, or exhibit some characteristic thought of as female, they are pegged. now, i'm not even curious. i think, if they are - that's their business and if they're not - too bad they're not married because they have a lot to offer - but maybe they're happy being alone.