They've got hit records, millions of fans, and the kind of success most musicians only dream of -- and they can't even legally uncork a bottle of champagne to celebrate their success. Welcome to Billboard.com's 2013 edition of 21 Under 21, our annual ranking of music's most powerful minors.

From bubbly boy bands (and a cool girl group) to hip-hop powerhouses, a sweet K-Pop princess to a rising EDM star, and of course, international pop icons, these are the fresh faces whose careers will continue to pack the biggest punches over the next 12 months. Get used to them all, because they're just getting started.

Billboard's 21 Under 21 List 2013