'Rock of Ages' Director: 'I Was Like a 15-Year-Old Girl' Hearing Tom Cruise Sing (Video)

Adam Shankman talks to THR about Warner Bros.' movie musical, which opens in theaters on June 15.

Director Adam Shankman had his work cut out with him when it came to taking the musical Rock of Ages and transitioning it to the screen. Sure, he had an all-star cast including Alec Baldwin, Russell Brand, Catherine Zeta-Jones, Julianne Hough, Malin Akerman and Tom Cruise, but he also had a group of actors that included some who had never sung in a film.

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Cruise, who plays rockstar Stacee Jaxx in the Warner Bros. film, is known for his full-on commitment to his characters, but could the man sing?

Shankman described to The Hollywood Reporter the first time he heard Cruise sing.

“The first time I heard him sing was before we formally agreed that we were going to go forward with this,” he said. Shankman sat in the other room as Cruise did his first lesson with Axl Rose’s former voice coach.

“He sounded amazing,” Shankman told THR. “And within one lesson his range broadened as he opened up. I opened the door, and I was like a 15-year-old girl, I was screaming and jumping up and down and going, ‘Oh my god this is going to work.’ ”

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For the film, which opens in theaters on June 15, Cruise worked on his singing voice for months.

“He was singing literally four or five hours per day. He wouldn’t stop, and I started to get scared he was going to blow out his voice,” Shankman said, adding that “There’s no 100 percent with him, there’s 10,000 percent.”

Shankman, who also directed the musical movie hit Hairspray, added that he was impressed by the level of commitment from all of the actors.

Who surprised him the most? Malin Akerman, who plays Rolling Stone journalist Constance Stark. Akerman’s character interviews Stacee Jaxx, but ends up falling for his rock star ways in one of the craziest scenes in the film.

“Because of her fearlessness and her willingness to let all of that insanity that she got embroiled in just sort of happen without blinking an eye,” Shankman said.

For her part, Akerman told THR it was an honor to work with Cruise.

VIDEO: 'Rock of Ages' Star Malin Akerman on Tom Cruise: 'He Transformed Himself Into a Rock Star'

"To be able to work with Tom Cruise is incredible,” said Ackerman. “If you look back at his body of work, he's such an incredible actor so I always feel like whenever you get to work with someone who's been in the business for a while whose really good at their job, they always make you a better actor."

Watch THR’s complete interview with Shankman above.

Email: Rebecca.ford@thr.com; Twitter: @Beccamford