1. (13)(last week) Firework-Katy Perry

LOS ANGELES, CA - JANUARY 05: Singer Katy Perry aka Katy Brand accepts the Favorite Female Artist and Favorite Pop Artist awards onstage during the 2011 People's Choice Awards at Nokia Theatre L.A. Live on January 5, 2011 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

2. (1) Forget You-Cee Lo Green

WASHINGTON, DC - MARCH 21: Cee Lo Green arrives at the Points of Light Institute Tribute to Former President George H.W. Bush at The John F. Kennedy Center for Performing Arts on March 21, 2011 in Washington, DC. (Photo by Kris Connor/Getty Images)

3. (2) Grenade-Bruno Mars

BERLIN, GERMANY - MARCH 24: Bruno Mars arrives for the Echo award 2011 at Palais am Funkturm on March 24, 2011 in Berlin, Germany. (Photo by Andreas Rentz/Getty Images)

4. (3) Perfect-Pink

LOS ANGELES, CA - NOVEMBER 21: Singer Pink performs onstage during the 2010 American Music Awards held at Nokia Theatre L.A. Live on November 21, 2010 in Los Angeles, California. (Photo by Kevork Djansezian/Getty Images for DCP)

5. (14) Raise Your Glass-Pink

LOS ANGELES, CA - NOVEMBER 21: Singer Pink arrives at the 2010 American Music Awards held at Nokia Theatre L.A. Live on November 21, 2010 in Los Angeles, California. (Photo by Jason Merritt/Getty Images for DCP)

6. (5) Jar Of Hearts-Christina Perri

NAPA, CA - NOVEMBER 13: Christina Perri poses at Aloft Hotels Presents Live in the Vineyard on November 13, 2010 in Napa, California. (Photo by Tim Mosenfelder/Getty Images for Aloft Hotels)

7. (16) For The First Time-The Script

BARCELONA, SPAIN - FEBRUARY 12: Singer Daniel O'Donoghue of the Irish band The Script peforms live during a concert at Razzmatazz on February 12, 2011 in Barcelona, Spain. (Photo by Javier Fernandez Del Corral/Getty Images)

8. (6) Tonight-Enrique Iglesias

NEW YORK, NY - DECEMBER 10: Enrique Iglesias performs during Z100's Jingle Ball 2010 at Madison Square Garden on December 10, 2010 in New York City. (Photo by Bryan Bedder/Getty Images)

9. (4) Marry Me-Train

LOS ANGELES, CA - FEBRUARY 13: (L-R) Musicians Scott Underwood, Patrick Monahan and Jimmy Stafford of the band Train accept the Best Pop Performance By A Duo Or Group With Vocals Award onstage during The 53rd Annual GRAMMY Awards held at Staples Center on February 13, 2011 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

10. (11) Back To December-Taylor Swift

WEST HOLLYWOOD, CA - FEBRUARY 27: Singer Taylor Swift arrives at the Vanity Fair Oscar party hosted by Graydon Carter held at Sunset Tower on February 27, 2011 in West Hollywood, California. (Photo by Craig Barritt/Getty Images)

11. (7) Rhythm Of Love-Plain White T's

NEW YORK - AUGUST 18: (L-R) De'Mar Hamilton, Tom Higgenson, Tim Lopez, Dave Tirio and Mike Retondo of the Plain White T's attend the benefit the VH1 Save The Music Foundation at Bowlmor Lanes on August 18, 2010 in New York City. (Photo by Astrid Stawiarz/Getty Images)

12. (10) We R Who We R-Ke$ha

DALLAS, TX - FEBRUARY 05: Singer Ke$ha performs onstage during the Bud Light Hotel event with performances by Nelly, Ke$ha and Pitbull on February 5, 2011 in Dallas, Texas. (Photo by Jordan Strauss/Getty Images for Bud Light)

13. (12) Stuck Like Glue- Sugarland

DENTON, TX - JANUARY 15: Singer Jennifer Nettles from Sugarland performs on stage during a benefit concert for the Attic Community Playground on January 15, 2011 in Denton, Texas. (Photo by Tom Pennington/Getty Images)

14. (8) Waiting For The End-Linkin Park

LOS ANGELES, CA - FEBRUARY 23: Singer Mike Shinoda of Linkin Park performs at the Staples Center on February 23, 2011 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

15. (9) Born This Way-Lady Gaga

PARIS, FRANCE - MARCH 02: Lady Gaga walks the runway during the Thierry Mugler Ready to Wear Autumn/Winter 2011/2012 show during Paris Fashion Week at Gymnase Japy on March 2, 2011 in Paris, France. (Photo by Francois Durand/Getty Images)

16. (18) Little Lion Man-Mumford & Sons

LONDON, ENGLAND - FEBRUARY 15: (UK TABLOID NEWSPAPERS OUT) Musicians Ted Dwane, Ben Lovett, Marcus Mumford and Winston Marshall of the band Mumford & Sons collect their award for Mastercard: British Album of The Year onstage at The Brit Awards 2011 held at The O2 Arena on February 15, 2011 in London, England. (Photo by Dave Hogan/Getty Images)

17. (19) Never Gonna Leave This Bed-Maroon 5

DALLAS, TX - FEBRUARY 04: Maroon 5 attends The Black Eyed Peas Super Bowl Party presented by Sports Illustrated and Bacardi at Music Hall At Fair Park on February 4, 2011 in Dallas, Texas. (Photo by Joe Scarnici/Getty Images for Bacardi)

18. (20) Rolling In The Deep-Adele

BERLIN, GERMANY - MARCH 24: Singer Adele attends the Echo Awards 2011 at Palais am Funkturm on March 24, 2011 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

19. (17) What The Hell-Avril Lavigne

NEW YORK, NY - MARCH 08: Avril Lavigne attends the release party for Avril Lavigne's new album "Goodbye Lullaby" at SL Lounge on March 8, 2011 in New York City. (Photo by D Dipasupil/Getty Images)

20. (26) More-Usher

LOS ANGELES, CA - FEBRUARY 13: Singers Usher (L) and Justin Bieber perform onstage during the 53rd Annual GRAMMY Awards held at Staples Center on February 13, 2011 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

21. (21) Sing-My Chemical Romance

LOS ANGELES, CA - MARCH 23: Singer Simon Le Bon of Duran Duran (L) and singer Gerard Way of My Chemical Romance perform onstage during "Unstaged: An Original Series From American Express" with a performance by Duran Duran and directed by David Lynch, in partnership with VEVO and YouTube, held at The Mayan on March 23, 2011 in Los Angeles, California. (Photo by Kevin Winter/Getty Images for American Express)

22. (22) When You're Young-3 Doors Down

GLENDALE, AZ - JANUARY 10: The band 3 Doors Down perform at halftime during the 2010 NFC wild-card playoff game between the Green Bay Packers and the Arizona Cardinals at University of Phoenix Stadium on January 10, 2010 in Glendale, Arizona. (Photo by Christian Petersen/Getty Images)

23. (24) Keep Your Head Up-Andy Grammer

24. (debut) Don't You Wanna Stay-Jason Aldean/Kelly Clarkson

25. (23) Closer To The Edge-Thirty Seconds To Mars

MADRID, SPAIN - NOVEMBER 07: Jared Leto and Shannon Leto of Thirty Seconds to Mars perform on stage at Puerta de Alcala on November 7, 2010 in Madrid, Spain. (Photo by Jordi Vidal/Getty Images)

26. (27) Uncharted-Sara Bareilles

LOS ANGELES, CA - FEBRUARY 09: Sara Bareilles performs at the 2nd Annual GRAMMY In The Schools Live! at USC Grand Ballroom on February 9, 2011 in Los Angeles, California. (Photo by Noel Vasquez/Getty Images)

27. (25) Hold On-Michael Buble

SYDNEY, AUSTRALIA - FEBRUARY 14: Micheal Buble performs on stage at Acer Arena on February 14, 2011 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)

28. (debut) ET- Katy Perry

LONDON, UNITED KINGDOM - MARCH 17: Katy Perry performs on the opening night of her 'California Dreams' UK tour at Hammersmith Apollo on March 17, 2011 in London, England. (Photo by Neil Lupin/Getty Images)

29. (29) All You Need Is Now-Duran Duran

LOS ANGELES, CA - MARCH 23: (L-R) Musicians John Taylor, Nick Rhodes, Simon Le Bon, and Roger Taylor of Duran Duran attend "Unstaged: An Original Series From American Express" with a performance by Duran Duran and directed by David Lynch, in partnership with VEVO and YouTube, held at The Mayan on March 23, 2011 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

30. (28) Stay The Night-James Blunt

LONDON, ENGLAND - FEBRUARY 15: Singer James Blunt arrives on the red carpet for The BRIT Awards 2011 at the O2 Arena on February 15, 2011 in London, England. (Photo by Ian Gavan/Getty Images)