Taking part in a star-studded event that celebrated the work of the ONE and (RED) organizations in pushing for more resources to fight AIDS, it seems as though Miley-bird was happy to be there.
In fact, she even told the audience:
"I just turned 23. And I know I will live in an AIDS-free world."
But the pop star might have been a bit too excited, because when she started singing with the U2 frontman and Jessie J, she kind of forgot the words to the rock band's pinnacle charity anthem One!
Bono brought out Jessie to sing the first verse of the song — but when Miley came out to sing the second verse, it was clear that she was a little rusty on the lyrics!