Metallica and Lang Lang rehearse for THE 56TH ANNUAL GRAMMY AWARDS music industry's premier event takes place Sunday, Jan. 26 (8:00-11:30 PM, live ET/delayed PT) at STAPLES Center in Los Angeles on the CBS Television Network. Photo: Heather Wines/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved

Revellers attend the 25th edition of the Sziget Festival on August 9, 2017 in Budapest, Hungary. The Sziget Festival, one of the largest music and cultural festivals in Europe, celebrates its 25th anniversary in 2017, taking place from August 9-16 on the Hajogyari Sziget in Budapest. (Photo by Laszlo Mudra/Rockstar Photographers)

Model Alessandra Ambrosio is seen at Coachella Music & Arts Festival at the Empire Polo Club on Friday, April 14, 2017, in Indio, Calif. (Photo by Hollywood To You/Star Max/GC Images)

Horsemen take part in the Durbar festival parade in Zaria, Nigeria September 14, 2016. It is celebrated at the culmination of Muslim festivals Eid al-Fitr and Eid al-Adha. It begins with prayers, followed by a parade of the Emir and his entourage on horses, accompanied by music players, and ending at the Emir's palace. (Photo by Afolabi Sotunde/Reuters)

KALTENBERG, GERMANY - JULY 08: Actors dressed as knights perform during the traditional Kaltenberg knight tournament on July 8, 2007 in Kaltenberg, Germany. With around 120,000 visitors each year, the festival including knight tournaments, medieval styled markets and a variety of music performances, the event is one of the biggest of its kind. (Photo by Johannes Simon/Getty Images)

Young people jump over a bonfire as they take part in the Ivan Kupala Night celebration, a traditional Slavic holiday, outside the small town of Turov, some 270 km south of Minsk, on July 6, 2016. People celebrate Kupala Night with bonfires that last throughout the night with some leaping over the flames as it is believed that the act of jumping over the bonfire cleanses people of illness and bad luck. (Photo by Sergei Gapon/AFP Photo)

Sunrise over Haleakala Crater, Haleakala National Park, Maui, Hawaii on April 26th, 2011. (Photo by Robert Bush/Alamy Stock Photo)

In this photograph taken on August 25, 2016, an Afghan shepherd watches over his sheep as they graze on the outskirts of Herat. (Photo by Aref Karimi/AFP Photo)