For the second year in a row, Justin Bieber has topped Billboard's "21 Under 21" list.

WENN reports that Bieber came just ahead of One Direction and Demi Lovato as the world's top musical act. 19-year-old country singer Scotty McCreery and 20-year-old rapper Mac Miller rounded out the top five, while Bieber's girlfriend Selena Gomez managed to come in sixth.