Singer Claudia Leitte (R) performs "We Are One" with Jennifer Lopez (L) and Pitbull at the 2014 Billboard Music Awards in Las Vegas, Nevada May 18, 2014. [Photo/Agencies]

2014 Billboard Music Awards

Jennifer Lopez was honored with Icon Award for lifetime achievement, and country singer Carrie Underwood won the fan-voted Milestone Award.

The show featured numerous performances, including from pop stars Shakira, Lopez, country duo Florida Georgia Line with country singer Luke Bryan, and Nickelodeon star Ariana Grande and Australian rapper Iggy Azalea.

Perry and Cyrus recorded performances from concerts in Britain to be shown at the awards. Cyrus performed a cover of the Beatles' 1967 song "Lucy in the Sky with Diamonds" with Wayne Coyne, the singer of rock group the Flaming Lips.

Rapper Pitbull kicked off the show alongside Lopez and Brazilian singer Claudia Leitte from the MGM Grand Garden Arena with a performance of "We Are One (Ole Ola)," the theme to next month's soccer World Cup in Brazil.