102 JAMZ Top 20 Countdown20. Calvin Harris - Feel So CloseHOLMDEL, 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 Countdown19. Drake - Started From The Bottomattends ESPN The Magazine's "NEXT" Event on February 3, 2012 in Indianapolis, Indiana.
102 JAMZ Top 20 Countdown18. David Guetta - I Can Only ImagineFrench DJ David Guetta performs at the Arena in Treptow, Berlin, on July 8, 2012. AFP PHOTO / FREDERIC LAFARGUE (Photo credit should read FREDERIC LAFARGUE/AFP/GettyImages)
102 JAMZ Top 20 Countdown17. Olly Murs - TroublemakerNEW YORK, NY - DECEMBER 07: Olly Murs performs during Z100's Jingle Ball 2012 presented by Aeropostale at Madison Square Garden on December 7, 2012 in New York City. (Photo by Kevin Kane/Getty Images for Jingle Ball 2012)
102 JAMZ Top 20 Countdown16. David Guetta - TitaniumFrench DJ David Guetta performs at the Arena in Treptow, Berlin, on July 8, 2012. AFP PHOTO / FREDERIC LAFARGUE (Photo credit should read FREDERIC LAFARGUE/AFP/GettyImages)
102 JAMZ Top 20 Countdown15. Rihanna - Diamondsperforms onstage during the 2012 iHeartRadio Music Festival at the MGM Grand Garden Arena on September 21, 2012 in Las Vegas, Nevada.
102 JAMZ Top 20 Countdown14. Lil Wayne/ Drake - Love MeORLANDO, FL - FEBRUARY 26: Hip-hop artists Lil' Wayne, wearing diamond studded beats headphones by Dr. Dre and Drake (L) sit courtside during the 2012 NBA All-Star Game at the Amway Center on February 26, 2012 in Orlando, Florida. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and or using this photograph, User is consenting to the terms and conditions of the Getty Images License Agreement. (Photo by Ronald Martinez/Getty Images)
102 JAMZ Top 20 Countdown13. 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 Countdown12. 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 Countdown11. Justin Bieber - Beauty And A Beatat The Staples Center on October 2, 2012 in Los Angeles, California.
102 JAMZ Top 20 Countdown10. 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 Countdown9. Bruno Mars - When I Was Your Man<> on November 7, 2012 in New York City.
102 JAMZ Top 20 Countdown8. Calvin Harris - Sweet NothingLOS ANGELES, CA - SEPTEMBER 06: DJ Calvin Harris poses in the press room during 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. Justin Timberlake - Suit & Tieduring the Opening Ceremony for the 39th Ryder Cup at Medinah Country Club on September 27, 2012 in Medinah, Illinois.
102 JAMZ Top 20 Countdown6. 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 Countdown5. Bruno Mars - Locked Out Of Heavenperforms onstage at the 54th Annual GRAMMY Awards held at Staples Center on February 12, 2012 in Los Angeles, California.
102 JAMZ Top 20 Countdown4. Taylor Swift - I Knew You Were Trouble performs onstage during the 2012 iHeartRadio Music Festival at the MGM Grand Garden Arena on September 22, 2012 in Las Vegas, Nevada.
102 JAMZ Top 20 Countdown3. Maroon 5 - DaylightXXX performs during the 2012 F1 Singapore on September 22, 2012 in Singapore.
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 CountdownBritney Spears & Will.I.Am - 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.