102 JAMZ Top 20 Countdown20. Ke$ha - Die Youngarrives at the 2012 MTV Video Music Awards at Staples Center on September 6, 2012 in Los Angeles, California.
102 JAMZ Top 20 Countdown19. P!nk - Just Give Me A Reasonattends the St. John's Health Center's Power Of Pink benefiting The Margie Petersen Breast Center at Sony Studios on November 12, 2012 in Los Angeles, California.
102 JAMZ Top 20 Countdown18. Justin Bieber - Beauty And A Beatat The Staples Center on October 2, 2012 in Los Angeles, California.
102 JAMZ Top 20 Countdown17. Olly Murs - TroublemakerLONDON, ENGLAND - JANUARY 16: Singer Olly Murs speaks on stage during the official launch to mark the FA's 150th Anniversary Year at the Grand Connaught Rooms on January 16, 2013 in London, England. (Photo by Ian Walton/Getty Images)
102 JAMZ Top 20 Countdown16. Maroon 5 - DaylightXXX performs during the 2012 F1 Singapore on September 22, 2012 in Singapore.
102 JAMZ Top 20 Countdown15. Krewella - AliveFestival goers enjoy a set by a dubstep DJ at the "Lounge on the Farm" festival near Canterbury in Kent, on July 8, 2011. Five years ago, dubstep was just another fresh but obscure strain of dance music, limited almost exclusively to a handful of nightclubs in south London. Today it is taking over dancefloors worldwide. Born out of drum'n'bass and the 2-step UK garage movement which propelled Craig David to fame, dubstep completed its journey from quirky curiosity to commercial success story earlier this month (eds: earlier in July) when DJ Fresh's "Louder" hit the top of the UK singles chart. AFP PHOTO/Leon Neal
TO GO WITH AFP STORY BY JAMES PHEBY *BRITAIN-ENT-MUSIC-DUBSTEP* (Photo credit should read LEON NEAL/AFP/Getty Images)
102 JAMZ Top 20 Countdown14.Swedish House Mafia - Don't You Worry ChildNEW YORK, NY - DECEMBER 16: (FOR EDITORIAL USE ONLY) DJ's Axwell, Steve Angello and Sebastian Ingrosso of Swedish House Mafia perform at Madison Square Garden on December 16, 2011 in New York City. (Photo by Michael Loccisano/Getty Images)
102 JAMZ Top 20 Countdown13. Bruno Mars - Locked Out Of HeavenLOS ANGELES, CA - FEBRUARY 12: Bruno Mars arrives at the 54th Annual GRAMMY Awards held at Staples Center on February 12, 2012 in Los Angeles, California. (Photo by Jason Merritt/Getty Images)
102 JAMZ Top 20 Countdown12. Calvin Harris - Sweet NothingHOLMDEL, NJ - MAY 20: DJ Calvin Harris spins onstage at 103.5 KTU's KTUphoria at PNC Bank Arts Center on May 20, 2012 in Holmdel City, New Jersey. (Photo by Brian Ach/Getty Images)
102 JAMZ Top 20 Countdown11. Demi Lovato - Heart AttackUS singer Demi Lovato performs under heavy rain in Montevideo, during her A Special Night tour on April 29, 2012. AFP PHOTO/Pablo PORCIUNCULA (Photo credit should read PABLO PORCIUNCULA/AFP/GettyImages)
102 JAMZ Top 20 Countdown10. Lil Wayne - Love Me
102 JAMZ Top 20 Countdown9. Rihanna - Pour It UpLONDON, ENGLAND - JULY 08: Rihanna performs at Barclaycard Wireless Festival at Hyde Park on July 8, 2012 in London, England. (Photo by Danny Martindale/Getty Images)
102 JAMZ Top 20 Countdown8. Taylor Swift - I Knew You Were TroubleLOS ANGELES, CA - SEPTEMBER 06: Singer Taylor Swift arrives at the 2012 MTV Video Music Awards at Staples Center on September 6, 2012 in Los Angeles, California. (Photo by Frederick M. Brown/Getty Images)
102 JAMZ Top 20 Countdown7. Pitbull - Feel This Moment<> on August 9, 2012 in Los Angeles, California.
102 JAMZ Top 20 Countdown6. Drake - Started From The Bottomattends ESPN The Magazine's "NEXT" Event on February 3, 2012 in Indianapolis, Indiana.
102 JAMZ Top 20 Countdown5. Bruno Mars - When I Was Your Manperforms onstage at the 54th Annual GRAMMY Awards held at Staples Center on February 12, 2012 in Los Angeles, California.
102 JAMZ Top 20 Countdown4. Rihanna - StaySinger Rihanna performs live on stage as part of her 777 tour at The Forum on November 19, 2012 in London, England.
102 JAMZ Top 20 Countdown3. Justin Timberlake - Suit & TieJustin Timberlake arrives for the premiere of 'Trouble With The Curve' on September 19, 2012 at the Regency Village Theatre in Westwood, California. AFP PHOTO/JOE KLAMAR (Photo credit should read JOE KLAMAR/AFP/GettyImages)
102 JAMZ Top 20 Countdown2. Macklemore - Thrift ShopSEATTLE - APRIL 08: Seattle recording artist Macklemore performs a tribute to Mariners broadcaster Dave Niehaus, who passed away last November, prior to the Mariners' home opener against the Cleveland Indians at Safeco Field on April 8, 2011 in Seattle, Washington. (Photo by Otto Greule Jr/Getty Images)
102 JAMZ Top 20 Countdown1. Will.I.Am / Britney Spears - Scream & Shoutat a taping of We Will Always Love You: A GRAMMY Salute To Whitney Houston on October 11, 2012 at the Nokia Theatre L.A. LIVE in Los Angeles, California. The show airs November 16, 2012.