This year's 21 Under 21 list — Billboard's annual ranking of the most important young artists, regardless of genre — includes heart-on-sleeve troubadours, big-tent electronic producers, a preternaturally gifted 12-year-old and the next big Latin boy band. Over the course of their relatively short careers, these artists have attracted the attention of the biggest stars in the world — Kanye West, Beyoncé, Drake, Ricky Martin — and taken home prizes from major shows like America's Got Talent and La Banda. They've accumulated No. 1 hits and No. 1 albums, Grammys and VMAs, and millions of followers on Twitter and Instagram, yet they still are aren't old enough to buy a beer in the clubs they sell out. Check out the next generation of stars below.