Honestly, the only thing that seperated Glam Rock from being a Transvestite was musical ability. If you could play an instrument, it was Glam Rock. If you couldn't.. well you were just a Transvestite.
Alot of great groups started out in glam, like Queen. I don't knock any of the glam or hair bands of the 80s and early 90s cause alot of good music came out of that time.