Rock of Ages (PG-13) ★★

A jukebox musical is the epitome of reverse-engineered entertainment. Take a set of songs linked together by a common thread, arrange them for Broadway belters, and fill in the gaps with enough narrative to convince the audience they're not sitting through a large-scale, cover band concert. Silly, satisfying and familiar — the perfect combination for a crowd-pleaser. Rock of Ages, the big screen adaptation of the hit stage musical, manages to make the simplistic formula feel even lazier. Starting off like a full-on '80s movie spoof, Rock of Ages quickly loses footing with a bombardment of overproduced tunes lip-synced by its celebrity cast. Simply put: it doesn't rock. At all.

The film opens with small town Kansas gal Sherrie Christian (Julianne Hough) hopping on a bus to make it big in Hollywood. There's a glimmer of hope as she duets Night Ranger's "Sister Christian" with a bus driver — maybe Rock of Ages really will be this fun and absurd. But when Sherrie arrives at The Bourbon Room, the city's premiere rock club and only second to Disneyland as the least threatening place in L.A., the movie spins out of control. Sherrie quickly strikes up a relationship with bartender/aspiring musician Drew (Diego Boneta), is hired by club owner Dennis Dupree (Alec Baldwin) and his second-in-command Lonny (Russell Brand), and becomes entangled in the joint's big attempt to stay afloat: the legendary Stacee Jaxx's (Tom Cruise) last concert before going solo.

Sticking with Sherrie as she explores the crazy hair metal scene is fun, but director Adam Shankman (Hairspray, Bedtime Stories) and his team of writers insist on piling more and more stuff on to Rock of Ages shoulders. There's politician wife Patricia Whitmore (Catherine Zeta-Jones) and her campaign against The Bourbon Room. There's Rolling Stone reporter Constance Sack (Malin Åkerman) who hopes to land one more interview with Jaxx. There's Jaxx's manager Paul Gill (Paul Giamatti), who responds to the fading rock scene with ambitions of starting a boy band with Drew. Anything that can open the door for more songs — pointless as the plot points may be — Shankman throws into the shuffle. Unfortunately, the ears can only take so much autotune.

The upside of the clunky script is some genuinely funny moments souped up by the comedic prowess of the supporting cast (a baboon named HeyMan throwing bottles at Giamatti, Cruise singing "I Want to Know What Love Is" into Ackerman's butt). Hough and Boneta have nothing to contribute to Rock of Ages, hammy leads with no material who pale in comparison to their '80s romantic predecessors. But the rest of the crew throw up sign of the horns and try their best to crank up the craziness, Baldwin and Brand making a case for a spin-off with their wacky rapport. A musical number in which the duo finally realizes their passion for one another would have made a great Funny or Die video, but padded with the filler of Rock of Ages, it has no room to shine. Even Cruise, who kills whenever he's musing full rock star mode, struggles to make the paper thin Stacee Jaxx work in his musical moments. The recordings are flat and lifeless, automatically putting a strain on the performers.

The music and the movies of the '80s share a similar aesthetic. They're over-the-top, they're hot and sweaty and they're about not giving a damn. Raw fun. Rock of Ages fails to capture that feel in both visuals and song, blowing out the flame of every lighter-waving moment with its stale recreation. For an energetic, entertaining two hours of classic rock tunes, stick to karaoke.