(FILES) This file photo taken on February 15, 2016 shows musician Stevie Wonder as he presents the Song of the Year on stage during the 58th Annual Grammy music Awards in Los Angeles. Stevie Wonder and Christina Aguilera will headline the long-anticipated tribute concert to late pop legend Prince, his estate announced on September 16, 2016 .The family said the concert -- the first and perhaps only public memorial to the music icon -- would take place October 13 at the 20,000-capacity XCel Energy Center in St. Paul, Minnesota. / AFP PHOTO / ROBYN BECKROBYN BECK/AFP/Getty Images