Singer Rihanna performs onstage during the 2011 Billboard Music Awards at the MGM Grand Garden Arena May 22, 2011 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images for ABC)

Singers Steven Tyler (L) and Nicole Scherzinger perform onstage at the iHeartRadio Music Festival held at the MGM Grand Garden Arena on September 24, 2011 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images for Clear Channel)

Santa Claus greets a child during a visit to residents of the slum of Petare in Caracas, Venezuela, December 11, 2016. (Photo by Ueslei Marcelino/Reuters)

A Nativity scene is seen at the window of a house in the medieval mountain village of Luceram as part of Christmas holiday season, France, December 15, 2016. Luceram presents more than 450 creches (Nativity scenes) from the tiny to the huge yearly in December as part of the Circuit des Creches. (Photo by Eric Gaillard/Reuters)

A skydiver dressed as Santa Claus prepares to leap out of a plane as 155 tandem skydivers set a new Guinness World Record over eight hours, over the Australian city of Wollongong, December 17, 2016. (Photo by Jason Reed/Reuters)

Blind and visually impaired Palestinian students walk down the stairs at a school, where they are taught English through song and music, at a school in the West Bank city of Hebron March 2, 2016. Palestinian students at a school for the blind in the West Bank are learning English through song, a welcome departure from using braille and memorising grammar rules. While students are delighted with the change, some parents in the religiously conservative town of Hebron are concerned that using music in the classroom jars with Islamic tradition. (Photo by Ammar Awad/Reuters)

Evan Leversage, who is terminally ill with brain cancer, is greeted by a Christmas decorated dog with his mother Nicole Wellwood (L), and his father Travis Leversage (2nd R) in St. George, Ontario, Canada October 24, 2015. Evan Leversage is a seven-year-old boy who has been living with inoperable brain cancer since he was two years old. His family has organized a Christmas celebration in October complete with a full parade, in case Evan does not live to celebrate his last Christmas day on the traditional date of December 25, according to local media. (Photo by Mark Blinch/Reuters)