102 JAMZ Top 20 Countdown20. Calvin Harris - So CloseLOS 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 Countdown19. Britney 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.
102 JAMZ Top 20 Countdown18. Maroon 5 - DaylightXXX performs during the 2012 F1 Singapore on September 22, 2012 in Singapore.
102 JAMZ Top 20 Countdown17. The Lumineers - Ho HeyNASHVILLE, TN - DECEMBER 05: Wesley Schultz, Neyla Pekarek, and Jeremiah Fraites of The Lumineers speak onstage at The GRAMMY Nominations Concert Live!! held at Bridgestone Arena on December 5, 2012 in Nashville, Tennessee. (Photo by Kevin Winter/Getty Images)
102 JAMZ Top 20 Countdown16. Selena Gomez - Come & Get Itonstage during the 2013 MTV Movie Awards at Sony Pictures Studios on April 14, 2013 in Culver City, California.
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. Justin Bieber & Will.I.Am - #thatpowerat The Staples Center on October 2, 2012 in Los Angeles, California.
102 JAMZ Top 20 Countdown13. Taylor Swift - 22LAS VEGAS, NV - APRIL 07: Singer Taylor Swift attends the 48th Annual Academy of Country Music Awards at the MGM Grand Garden Arena on April 7, 2013 in Las Vegas, Nevada. (Photo by Jason Merritt/Getty Images)
102 JAMZ Top 20 Countdown12. Macklemore - Thrift ShopCULVER CITY, CA - APRIL 14: Rapper Macklemore performs onstage during the 2013 MTV Movie Awards at Sony Pictures Studios on April 14, 2013 in Culver City, California. (Photo by Kevork Djansezian/Getty Images)
102 JAMZ Top 20 Countdown11. Justin Timberlake - Suit & TieAUSTIN, TX - MARCH 16: Justin Timberlake performs at Myspace Secret Show @ SXSW on March 16, 2013 in Austin, Texas. (Photo by Jason Kempin/Getty Images for Myspace)
102 JAMZ Top 20 Countdown10. Fall Out Boy - My Songs Know What You Did In The Darkperforms during All-Star Saturday Night part of 2013 NBA All-Star Weekend at the Toyota Center on February 16, 2013 in Houston, Texas. 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.
102 JAMZ Top 20 Countdown9. Demi Lovato - Heart AttackLOS ANGELES, CA - FEBRUARY 14: Recording artist Demi Lovato attends the Topshop Topman LA Grand Opening at The Grove on February 14, 2013 in Los Angeles, California. (Photo by Frederick M. Brown/Getty Images)
102 JAMZ Top 20 Countdown8. Pitbull - Feel This Moment<> on August 9, 2012 in Los Angeles, California.
102 JAMZ Top 20 Countdown7. Icona Pop - I Love ItNEW YORK, NY - SEPTEMBER 06: Singers Caroline Hjelt (L) and Aino Jawo of the musical group Icona Pop attend the Nicholas K Spring 2013 fashion show during Mercedes-Benz Fashion Week at The Studio at Lincoln Center on September 6, 2012 in New York City. (Photo by Stephen Lovekin/Getty Images for Mercedes-Benz Fashion Week)
102 JAMZ Top 20 Countdown6. Calvin Harris & Florence Welch - 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 Countdown5. 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 Countdown4. 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 Countdown3. Justin Timberlake - MirrorsAUSTIN, TX - MARCH 16: Justin Timberlake performs at Myspace Secret Show @ SXSW on March 16, 2013 in Austin, Texas. (Photo by Jason Kempin/Getty Images for Myspace)
102 JAMZ Top 20 Countdown2. 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 Countdown1. Macklemore - Can't Hold UsMacklemore and Ryan Lewis perform live at Nova's Red Room at The Cullen Hotel on February 13, 2013 in Melbourne, Australia.