about male singers...
When I think of masculentity, I think of the lone cowboy on the trail, or the lone-wolf in some endeavour. You'll never see two truck drivers wanting to go to the bathroom together for moral support. They're lone-wolves.
The few notable exceptions in male singers and why I think they're notable:
Prince: I don't think he's gay. He may be bi, but I don't think he's gay (and even if he is, he's singing for you - not screwing you, so it doesn't matter). I think he's an extemely talented, driven virtuoso. Men who are jealous that he's scoring hotter chicks than they could ever get: you should be as "gay" as Prince.
Bon Jovi and John Mellencamp: neither one of these guys are what I'd call gifted singers. They're good, but they're not great - at singing. In my opinion, this is what they're great at: putting together a consistent package in terms of combining their looks, image, lyrics and lifestyle, and making all of those things form the tip of the spear that allows them to penetrate the rest of the riff-raff, propelling them to the top. Also, both of these guys have exceptional guitarists - which Bruce Springsteen lacks - or he'd be in the same category.
Bob Segar: gifted. A bit of advice: take some happy pills when writing your songs.
Mick Jagger: gifted.
Robert Plant: not an all-around singer, but no one can mimick a white woman coming to orgasm because of a black man better than you.
Trace Adkins: you suck as a singer, but your lyrics and personality set you apart. I dig the deep voice, I just wish you were on key. Is it too much of your sound engineers to electronically tweak your voice in the studio so at least your recordings are on key?
Micheal McDonald: gifted, but I'd never buy your CDs - but you are gifted.
And last but not least: Taylor Hicks. Everyone is asking, "What happened with him?" I've got a theory: I think he's the kind of guy who's going to do his own thing, regardless of what the contract may have stipulated. If he's not allowed to do his own thing (which it's obvious, he isn't) then I think he'll do as little as he can get away with, and through the goofy grin and likeable personality, tell the powers-that-be to politely fuck off, because I think as long as he can at least make a meager living doing what he loves, he doesn't care about the stardom - which makes me like him that much more than the rest.
Other than these guys (and maybe a few others who didn't get mentioned only because I can't think of them right now) I don't think of singing as a male thing.
I think people of both genders like singers to be hot sirens who can be both passionate and tender - and win the swimsuit competition if they had to.
That's just my theory.