I typed in "Neil Sedaka" gay, and you may be right. He's a big supporter of something called Amfar since his long-time partner (*songwriting* partner, wink) died of AIDS. Also, in some British play, he played a gay bodybuilder who is married. The page with the AIDS info claimed he wasn't gay, but I'm not taking their word. In fact, I'm clearing my browser history since their url contains the word "queer" in it.
Thanks for the follow up.