Tom Cruise was very "intense" while working on anticipated musical film Rock of Ages.

The Hollywood star plays musician Stacee Jaxx and had to learn all the dance moves of an 80s rocker.

But head choreographer for the film, Mia Michaels, said being around the A-list actor was a fun ride although challenging.

"Working with Tom really was a game changer for me," Mia told OK! magazine. "I'm a huge, huge fan after working with him."

"It was so intense and so awesome because he has the fearlessness of a child when he's diving into a character. There's just no ego."

Mia says Tom's passion for life and his art is evident on and off the screen.

"He's a complete workhouse," she gushed. "When he's given a challenge, he takes it on 100% and he doesn't stop."

"We were rehearsing four to five hours a day, every day, and it was about drilling those gestures and that physicality. It was so cool watching the transformation in Tom. He wasn't a dancer, but he became this crazy, quirky, like physical dancer and performer and it looked so natural."