The Bachelor alum didn't exactly have fond memories from her time in NYU's prestigious musical theatre program with the now-pop star.
The Rain On Me singer joined the rockers on stage at Las Vegas' Sphere for a surprise turn.
More than a decade on from her untimely death, the iconic star's legacy lives on.
Madonna, Lady Gaga and Beyoncé are just three of the stars who've made headlines at the ceremony in past years.
Featuring Britney's snake, Miley's foam finger and Beyoncé's big reveal.
The rock group are back with a new album, new single Angry and a new music video – featuring an A-list cameo.