According to "Rock of Ages" director Adam Shankman, without Tom Cruise's portrayal of Les Grossman in "Tropic Thunder," the actor may have never been offered the role of veteran rocker Stacee Jaxx.

That's somewhat surprising, considering how invested Cruise seem in the film, an adaptation of the popular Broadway musical about a small-town girl (Julianne Hough), her barback boyfriend (Diego Boneta) and the denizens of the Sunset Strip club, The Bourbon Room.

Here, Shankman takes us through the process of casting Cruise as well as how he brought the musical production of "Rock of Ages" to your local movie theater (something he also did with the musical version of "Hairspray"). He also explains why Paul Giamatti wound up with a face full of baboon ass.

When did you decide, "You know, I need to direct 'Rock of Ages'"?
What happened was -- totally the truth -- I was developing a few projects. And the New Line guys -- who I had a fantastic experience with on "Hairspray" -- said, "We really want you to do this." And I said, "I really don't know what it is." They gave me tickets to see it in New York, I went to see the show -- and the show was almost less a trip than how insane the audience was for it. I'm sitting there going, "Oh my God, what's happening in this room"? I could barely watch the show because people were singing. A girl four seats down threw up on the person in front of her because she was so drunk. But when I went to them, I was like, "Guys, I can do all of the funny -- you do realize that the story gets dark."

Speaking of that, Stacee Jaxx is a lot less dark in this movie than he is in the musical.
Well, the Stacee Jaxx character, why he's not ... the truth of the matter is that a real rock star -- and, believe me, Tom Cruise was a very famous, famous man in the '80s and he knew a lot of rock stars. The truth is, these guys were not "bulls in a china shop" -- they were children who were never alone. If you notice in the stage production, Stacee never had any one around him. Then he does weird things. Like, he randomly has Sherrie fired for no reason. Why would he do that? He didn't even know who she was -- she's just another piece of ass. He wouldn't care. So, we just said, "We have to find a new truth for this guy." If you read the biography of these guys, they all lived intensely on stage. When they got off stage, one step off stage, and their lives went to hell. They did not know how to live in the real world.

You mention the audience experience of the musical. Are you worried that might be hard to recreate in a movie theater? That people should see this with a rambunctious audience?
You know what? It's the dream experience, but you can't get worried about it. One of the things I've learned in my life and in my job is that there are things I can't control. I can only try to make something as fun as it is. Listen, there's nothing like seeing live musicians play. Right away, that makes you feel like you can make noise. And, by and large, movie theaters are places where people are saying, "Shhh!" What I have experienced with people watching this movie, regular audiences, you see a lot of people head banging and bopping around and singing. I did it as well as I can do it and, past that, I can't be worried about people sitting in quiet audiences -- I would be a nervous wreck. I'd be popping Xanax like Tic Tacs.

The film is set in 1987, but as far as the music goes, the year doesn't seem to be a concern. At one point "I'll Remember You" by Skid Row plays in the background, which was released in 1989.
That's from the play. If you look at all of the original songs in the play, they certainly weren't released at the same time. It's a fantasy and more of a tribute. And just by its very nature, I wasn't trying to make anything that was, to the letter, historically accurate. I just wanted it to be as close as possible.

Did you like having a baboon on set?
I actually love Micky. Micky and I got along great. I think some of the actors were a little trepidatious around him, occasionally.

Julianne Hough mentioned that she was scared of being mauled.
[Laughs] That's funny. I mean, the one who should have been scared is Paul Giamatti. You know, Paul is such a brilliant actor and baboons are really, really sensitive and they sense energy. And when Paul is yelling at Diego, the baboon did not like it. He would kind of cower and then he would stick his ass in Paul's face. It was like ... he expressed displeasure, I'll tell you that.

Please tell me that we'll get to see that on a DVD outtake.
I think the gag reel is going to be on the DVD and I think that is on there.

Were you always on board with Tom Cruise playing Stacee Jaxx?
There was a year of talking about it. And, very specifically, him in "Tropic Thunder" was his audition. That is why I thought of him. He was so "all in" in a comedy that I knew that he would go for it in unimaginable ways. And what was really important is that he doesn't make fun of these characters. He just is them and kind of lives their truth. Once we discovered what his version of Stacee Jaxx's sort of truth was ... Tom is an actor who really loves directors. He likes talking directors and he likes to be directed. He does not go out there and say, "It's my way or the highway." I said, "If we take your intensity and make it that you're intensely lost," like so many of these guys were -- there was nothing bad about throwing a TV out of the window or being with 20 girls for the night. And in his mind, he sees himself as this lonely cowboy, drifting alone in the desert. And he's like, "I totally get that."

An ongoing joke of the stage production was that they couldn't afford any Def Leppard songs. There are Def Leppard songs in this movie.
When Def Leppard heard that in no way, shape or form were we making fun of the period or their music or themselves, they opened up. As did Joan Jett. As did Guns 'n' Roses. So, Axl gave us that. I think everybody felt like they were in really good, safe hands.

Mike Ryan is senior entertainment writer for The Huffington Post. He has seen Rock of Ages on Broadway twice. You can contact Mike Ryan directly on Twitter.

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