If you like rock musicals, you might like some of it. Rock of Ages is kind of stupid, kind of cool rock opera that nearly passes for its musical numbers. When it goes into arbitrary dialogue or soap-opera melodrama it goes limp. The central love story between Julianne Hough and Diego Boneta is too tweeny. Yet for all of the bubblegum elements the movie has very adult stuff – lewd gestures, acts of self-degradation and a strip club detour. It wants to be Naughty but Nice. Alec Baldwin, as the Bourbon Room club owner who needs to raise money to save his business(!), has a throwaway scruffy humor. But Tom Cruise, who isn’t 25 or 35 or 50, steals the show as the legendary Stacee Jaxx. He isn’t any of those ages, because he’s ageless.

This is the kind of music-kaleidoscope fantasy where every hit ’80’s song, including “Paradise City,” “Rock You Like a Hurricane,” “Pour Some Sugar On Me,” and best, “Wanted Dead or Alive,” seem to be under the rights of Stacee Jaxx and belong to nobody else. Tom Cruise plays Jaxx like T.J. Mackey on Quaaludes.

I wish we didn’t have to endure the embarrassing scenes with Catherine Zeta-Jones. There was once a hint that she was a rock groupie scorned, but now as a local righteous church type, she is leading a coalition to have the Bourbon Room shut down (Rock n’ Roll is the work of the devil, stuff like that). Do we really need an outfit of puritanical moms’ doin’ the “Beat It” Michael Jackson moves while belting out “Hit Me with Your Best Shot?” The gleaming clean look of the visuals and the choreography clash awkwardly against any scene inside the decadent Bourbon Room.

Yet the key reason why the movie doesn’t completely hold you is because of this. Tonal shifts, arbitrary plot predicaments, characters going through changes of heart – this all mucks up the movie into television tween-ville. And yet the darker stuff just makes you feel… uncomfortable. I was torn – I liked Malin Akerman on her knees under Cruise (Malin, right under Cruise’s pelvis), the two of them in duet to “I Want to Know What Love Is,” at the same time wondering what would the “High School Musical” fan-set think of that? How about the NCA groups?

Of the two background characters Russell Brand (as a club asst. manager) and Paul Giamatti (record label artist manager), I’d say Giamatti has the juicier work. Giamatti can’t sing a damn, but he has two memorable lyrics. Uh, the lyrics aren’t memorable, but watching him do it is. Back to the leads: Hough brings alive that pretty Oklahoma girl fantasy to boy audiences out there. She’s the fresh farm girl gone music-club rebel. As long as they keep making movies like “Rock of Ages” Hough will continue to look good in them.

Based on a Broadway show. Originally did not feature the Zeta-Jones character.

123 Minutes. Rated PG-13.

MUSICAL / GOOFY / WEEKEND VIEWING DEBAUCHERY

Film Cousins: “Velvet Goldmine” (1998); “Rent” (2005); “Hairspray” (2007); “Burlesque” (2010).

Official movie website: click here.