Seems to me that certain performers, certain music producers, certain musical styles, may be adopted by the Gay community and, therefore, become identified as 'Gay music'. As such, it might be regarded by some as a representation of 'Gayness'. Kylie, the Communards, Pink, much of the electro-pop of the '80s, all say 'Gay' to me, but my wife doesn't see it.

But is the music itself Gay? Nope, don't think so. It's not the music per se, it's how people relate to it, what they were experiencing and where they were when they first heard it, and lots of other influences affecting their perception.

IMHO, YMMV.