The Mission: Impossible actor plays rocker Stacee Jaxx in the film, and will be performing Bon Jovi's 'Dead or Alive' at the filming.
Director Adam Shankman has launched a Facebook campaign for extras to attend scenes at the Sun Life Stadium in Miami, Florida on Monday.
Cruise revealed: "It's a concert scene and it's [me singing] 'Dead or Alive' and it goes into where Stacee's performing in a stadium and so there'll be a big show.
"Then, there's another song, [Journey's] 'Don't Stop Believin', where the whole cast will be on there and we'll perform that."
The star was talking to Ryan Seacrest, whose girlfriend Julianne Hough also stars in the movie. He added: "It's fun. I've never done a musical and I'm having a blast. I love this character.
"I saw Adam [Shankman] a few years ago after I saw Hairspray and I said, 'Okay, man, where's our musical?', and he came to me with this."
Stephen Baldwin recently described Tom Cruise's singing in Rock of Ages as "intergalactic".
> Tom Cruise posts Rock of Ages picture
Watch the trailer for Tom Cruise's upcoming Mission: Impossible - Ghost Protocol below: