nowadays i have no clue. like why the hell did they make JB famous, i know a ton of people who are my friends who can sing and play guitar a thousand times better than him and yet they arent famous. so i cant really give you an answer to that
Have a talent. Put it to work. Be original with it. Work hard. Work hard some more. Fail a couple times (at least). Work hard again. And there you are. For a while. Fame, especially if you can't back it up, is fleeting.
Become friends with someone in a big record company (or something similar). Remember though, being famous doesn't mean you're good at what you do. Just look at all these talentless "musicians" like JB and Lady Gaga. They have no talent and yet they're famous. It's just sad. We need to go back to the music of old, with people like Guns n' Roses, Aerosmith, Van Halen, etc.