12. Meghan Trainor: 21 Under 21 (2014)
Birthdate: Dec. 22, 1993 (Age: 20)
Last Year's Rank: N/A
Why She's Hot: People speak of "surprise hits" all too glibly these days, but Meghan Trainor's "All About That Bass" is truly a left-field success story. Who would have predicted that a positive body-image anthem done in the style of '50s doo-wop would dominate the Billboard Hot 100 this year? But the ubiquitous "Bass" is just the beginning for the Massachusetts singer-songwriter. She penned two tracks on Rascal Flatts' 2014 album Rewind and just released her debut EP, Title, which hit No. 15 on the Billboard 200. Trainor tells Billboard she's comfortable as a poster girl for empowerment: "If you asked me, 'What do you want to say?' it would be, 'Love yourself more.'"
Billboard's 2014 21 Under 21 List