Written by . Published: September 19 2012
Justin Bieber has topped Billboard's 21 Under 21 list for a second successive year.
The Baby singer has been named the world's top young musical act, ahead of boy band One Direction and Demi Lovato.
Rounding out the top five are country singer Scotty McCreery, 18, and rapper Mac Miller, 20.
Bieber's girlfriend Selena Gomez comes in sixth.