Adam Shankman Hopes for Constantine Maroulis Cameo in Rock of Ages Film; Talks Tom Cruise Singing

With newcomer Diego Gonzalez Boneta now officially cast as Drew in Adam Shankman's upcoming Rock of Ages film, the director says he's open to the possibility of Tony-nominated stage star Constantine Maroulis appearing in the film. "Constantine was a total inspiration, and he was fantastic, and I still have every intention of using him in the movie," Shankman told EW.com. "I'd love to cameo him or have him say something. I think it would be a great show of support."

Shankman explained his decision to cast Boneta over Maroulis, who had expressed interest in the movie. "I am deeply committed to casting at authentic age," he said. "I don't want to have to ask anybody to act like they are 23. I wanted a 23-year-old." (Maroulis, who is currently on tour with Rock of Ages, is 35; Boneta is 20.) "[Boneta] is a kid who came to Los Angeles with a dream and who sings and has an amazing voice and drive. And he's also as honest and sweet as you can possibly make him."

As the May 19 filming start date approaches, does Shankman feel his other leading man, Tom Cruise, is ready to tackle the musical's demanding rock vocals as Stacee Jaxx? "He's singing five hours a day; he's gonna start doing rock-star boot camp," Shankman said. "Here's the thing about Tom Cruise: I knew in my heart he would never put himself in harm's way about taking on a part if he didn't think he could deliver. So it wasn't until our first go around with his voice lesson that we sort of looked at each other and went, 'This is gonna work!' And we were basically dancing around the living room and high-fiving each other because he actually has a fantastic voice."

Shankman also noted that Amy Adams, Russell Brand and Paul Giamatti are all still in negotiations to join the cast. The film is expected to hit theaters in summer 2012.