Billboard.com has released their list of 2011 21 Under 21, which features the 21 hottest musicians under 21-years-old! Coming in at #1 and as not much of a surprise, 17-year-old superstar Justin Bieber.

Justin moved up one spot from the last years, #2 positioning. Also, moving up in the ratings is 14-year-old Cody Simpson, who went from #20 last year to #13, along with Disney star Demi Lovato, moving up one spot from #8 to #7. Well done!

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On the other hand, a few of our favorite stars took an unexpected fall on the list; Miley Cyrus, who was #10 last year, barely made the cut, coming in at #21.  Will Smith and Jada Pinkett Smith's daughter Willow Smith fell seven places, coming in at #14 and Greyson Chance was ranked #15, down six spots from last year's #9. Actress/singer/Justin Bieber's girlfriend, Selena Gomez, held on to her #3 spot for the second year in a row.

Here is the complete list:

21. Miley Cyrus - 18

20. Miguelito - 12

19. One Direction - Liam payne 18, Zayn Malik 18, Harry Styles 17, Louis Tomlinson 19, Niall Horan 18

18. Porter Robinson - 19

17. HyunA - 19

16. Mindless Behavior - Prodigy, Princeton, Ray Ray, Roc Royal - All 14

15. Greyson Chance - 14

14. Willow Smith - 10

13. Cody Simpson - 14

12. II Volo - Gianluca Ginoble 16, Ignazio Boschetto 16, Piero Barone 18

11. Lex Lugar - 20

10. Victoria Justice - 18

9. Rye Rye - 20

8. Nick Jonas - 19

7. Demi Lovato - 18

6. Mac Miller - 19

5. Jackie Evancho - 11

4. Scotty McCreery - 17

3. Selena Gomez - 19

2. Tyler, The Creator - 20

1. Justin Bieber - 17

Noticeably missing from this year's list are Taylor Momsen and Miranda Cosgrove.

Who do you think are the hottest young musicians?

Photos courtesy of Fame Pictures