Are you suggesting that if MIDI files were to find other MIDI files of the same gender, that they would be attracted to them? Or more accurately, that MIDI files are happy? Why wouldn't you want to include 'happy' files on your webpage?
Sorry, it bugs me when people misuse the word 'gay' to mean 'bad'.
And for the sake of web users everywhere, please _please_ include an easy option to turn the music off, or better et, make the user click to hear the music, because there is nothing more irritating than having a page suddenly start blaring some song over whatever other sounds my comptuer is making that I want to hear.