Justin Bieber shakes hands with US boxing champion Floyd Mayweather Jr as his mother Pattie Mallette looks on during the Los Angeles Clippers - Oklahoma City Thunder NBA Western Conference semi-final game at the Staples Center in Los Angeles, California, on May 11, 2014.
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Jason Derulo attends the 2014 CMT Music awards at the Bridgestone Arena on June 4, 2014 in Nashville, Tennessee.
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Tim McGraw performs during the opening night of his Sundown Heaven Town Tour at Save Mart Center on May 8, 2014 in Fresno, California.
Jay-Z performs at Barclays Center on September 28, 2012 in the Brooklyn borough of New York City.
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Pete Wentz of Fall Out Boy poses backstage during the 22nd Annual KROQ Weenie Roast at Verizon Wireless Music Center on May 31, 2014 in Irvine, California.
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Ben Haggerty aka Macklemore performs live for fans as part of the 2014 Future Music Festival at RNA Showgrounds on March 1, 2014 in Brisbane, Australia.
Wiz Khalifa arrives at Ditch Fridays during Memorial Day weekend at the Palms Casino Resort on May 24, 2013 in Las Vegas, Nevada.
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Harry Styles of One Direction performs at the Velez Sarsfield stadium in Buenos Aires, Argentina, 03 May 2014, during the band's Latin American tour.
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Afrojack visits SiriusXM Studios on May 1, 2014 in New York City.
Drake performs in concert at the AT&T Center on November 12, 2013 in San Antonio, Texas.
Tyler Hubbard and Brian Kelley of Florida Georgia Line perform during the 2014 CMA Festival at LP Field on June 7, 2014 in Nashville, Tennessee.
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Ashton Irwin of the boy band 5 Seconds of Summer seen leaving the Pantechnicon pub in Knightsbridge on June 08, 2014 in London, England.
David Guetta performs during the David Guetta Party at The Gotha Club on August 3, 2013 in Saint Tropez, France.
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Brantley Gilbert performs at LP Field at the 2014 CMA Festival on June 5, 2014 in Nashville, Tennessee.
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Roc Royal of Mindless Behavior performs at the Nokia Theatre on July 6, 2013 in Los Angeles, California.