Why do rock stars sometimes scream and growl when singing?

not just that but its the type of genre. its like why do opera singers have to sing so high their noses can bleed? its jsut how they want it to be sung, also rock I am guessing you mean heavy rock, well it has that image. also u have many subgenres of rock an same goes for metal and some metal involves pure growling and screaming while some are melodious in most ways

its a style of music… Why do people have a country “twang” in there voice? Or why does Christina Agulara hold a note as a high soprano for a minute and a half? Why do the black eyed peas suck so bad live? Haha… Because thats the music industry. to diverse yourself from others, to stand out and make your own name for yourself.

Why do some vocalists sing when they’re growling and grunting?

Musicians tend to have a lot of emotional attachment to their singing. Some songs might elicit that sort of reaction with their voice. Some times it is a stylistic choice, but a lot of the times it is not on purpose. They just feel very connected to the music to where they might get a little emotional.

I don’t know…but I think it’s sexy…usually.

Depends what genre you’re talking about, some people get metal, rock and screamo mixed. Screamo has screaming cuz… well. The clue is in the name :3 Rock and metal sometimes has it to add emotion or to reinact an event. Amy Lee of the metal/rock/classical band Evanescence screams ‘I long to die!’ in Tourniquet to ‘play the role of the person wanting to rest at last’.