Mariah Carey is going to perform at the Billboard Music Awards after a 17-year break.
The singer is the only artist to have scored 18 Hot 100 number one singles in the States.
Tonight, Mariah begins her Las Vegas residency in which she will perform all of her number 1 hits, three nights a week.
Mariah has promised fans who come to the show a great time.
"This is a fun place to be…I'm really enjoying myself," she said.