'Rock of Ages' Stars Julianne Hough, Diego Boneta Train Their Voices for '80s Rock (Video)

The former "Dancing With the Stars" professional dancer tells THR she had to get rid of "certain twangy things" in her country singing voice to handle the songs in Warner Bros.' movie musical.

Rock of Ages follows two young aspiring singers who work in a bar on the Sunset Strip while they try to make it in the rock n’ roll business.

Julianne Hough, formerly a professional dancer on Dancing With the Stars and currently a country singer and an actress who recently starred in Footloose, plays Sherie, a wide-eyed blonde from Kansas who gets mugged in her very first moments in Hollywood.

PHOTOS: 'Rock of Ages' Premiere Features Tom Cruise and Julianne Hough, plus Josh Duhamel and Fergie in Costume

She’s helped out by Drew (Diego Boneta), a busboy at the infamous Bourbon Room, who gets her a job waiting tables.

The film, directed by Adam Shankman, is Boneta’s very first feature film, which understandably made the 21-year-old a little nervous. Boneta, who is a Mexican pop singer and released his debut album, Diego, in Mexico, Chile and Brazil in 2005, had to change his voice to fit the rawness of '80s rock.

“I was nervous about the singing because these songs are so high,” Boneta told The Hollywood Reporter. “And it was learning to sing with this rocker voice, which is something really new for me.”

As for Hough, 23, she said she loved the entire experience: from the singing, to the dancing and the acting.

“I was just excited. I don’t think I was worried,” she said. “Those are the three most amazing things that I love to do, so I was thrilled that I got to go all three in one movie.”

FILM REVIEW: Rock of Ages

Hough, who released her self-titled debut album in 2008, says that because she sings country music, she did have to retrain her voice to handle the ’80s rock songs that are featured in the film.

“I had to definitely grow a bigger range,” she told THR. “The songs are extremely high, so lots of vocal training. I sing country so I had to take away my dips and certain little twangy things I said. It was hard.”

Hough and Boneta weren’t the only ones rocking out in the Warner Bros. film  --  Tom Cruise takes a turn at singing as rockstar Stacee Jaxx. Cruise trained for months with a vocal coach to perfect his singing for the role.

“That was the most dedicated, committed performance I’ve ever seen,” Hough said of Cruise’s work. “He literally is Stacee Jaxx.”

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

The film, which based on the musical of the same name, features dozens of classic ‘80s songs. When asked which song was closest to their hearts, Boneta was quick to point to “Waiting for a Girl Like You”

“That’s the song I auditioned with. So that song changed my life,” he told THR.

Rock of Ages, which also stars Catherine Zeta-Jones, Alec Baldwin, Russell Brand and Malin Akerman, opens in theaters on June 15.

Watch THR’s full interview with Hough and Boneta above.

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