Hollywood -- Critics have rightly lauded the dynamic visuals of "Children of Men," citing the work of director Alfonso Cuaron and cinematographer Emmanuel Lubezki. In depicting the story's breakneck action through the totalitarianism and decay of 2027 Britain, the filmmakers have created a vision of the not-so-distant future that is alien and terrifyingly familiar.

Similarly perceptive is Cuaron's use of sound -- especially music -- in delineating a world where Britain appears to be the last society standing, immigrants are caged or forced into refugee encampments and a baby has not been born in 18 years. Eschewing a traditional score, the director combines rock, pop, hip-hop and classical pieces to create one of the most unconventional cinematic soundscapes in recent memory.

The music is used inventively and sparingly, saving us from the wall-to-wall scoring that plagues so many films and providing the film's protagonist, Theo -- an activist turned minor bureaucrat, played by Clive Owen -- with a sonic path through London, East Sussex and Kent. Burned out and alcoholic, Theo is appalled at the state of things when he is drawn into the plans of a radical group seeking rights for immigrants, headed by a former paramour (Julianne Moore).

The movie's London is a bustling police state in which people still stop off for coffee on their way to work but must pass through checkpoints and barricades to do so. Cuaron mixes the sounds of traffic, barking dogs and a narcotized stream of media messages (including ads for a state-sanctioned suicide kit) with grimy hip-hop dubs to create an urban audio rumble.

Outside the city, life appears serene -- save for the marauding hordes, who have a penchant for ambushing passersby, and the piles of burning cattle corpses. Theo takes the train to visit his old friend Jasper (Michael Caine), a former political cartoonist who lives with his comatose wife in a secluded house where he grows gourmet pot. He's an old-time hippie with long hair, leftist politics and John Lennon glasses, and his car radio blasts Deep Purple's "Hush." In the context of the movie, the song becomes a sly lullaby for a world without babies.

It's not surprising that Jasper would be fond of classic rock, and twice at his home we hear a melancholy cover of the Rolling Stones' "Ruby Tuesday." Sung by Italian songwriter Franco Battiato, it underlines Jasper's sympathies and foreshadows the cacophony of accents heard later at a refugee camp.

In the film's second half, Cuaron uses less pop music and relies more heavily on augmenting silence with jarring sound effects -- the burst of automatic weapons fire, say, or the squawk of loudspeakers ordering fugees, as illegal immigrants are called, through a maze of cages. The coastal town of Bexhill, transformed into a giant refugee camp that operates as a Third World city with a black market economy, is chaotic and troubling. Into the anarchy, Cuaron injects classical works by Handel and Mahler as well as "Threnody for the Victims of Hiroshima" (1959-1961) by Krystof Penderecki.

The thread that holds this crazy quilt of sounds together is British composer John Tavener's "Fragments of a Prayer," a 15-minute commissioned piece that Cuaron envisioned as "a spiritual comment rather than a narrative support." Tavener wrote it based on the screenplay, in contrast to the traditional method of scoring to a film's images.

The director initially introduces the piece after a tragedy and then strategically places segments throughout the film, developing it as a motif. A sacred entreaty with recurring hallelujahs, it features mezzo-soprano Sarah Connolly and reinforces the idea of faith defying the malevolence of chance. By the end of Theo's journey, the theme has built to a complex emotional level that coincides with the film's climax.

After a provocative ending that keeps audiences in their seats for the credits, "Children of Men" continues to reward aurally, finishing strongly with two politically pointed songs. Leaving us with Lennon singing the anti-nationalist rant "Bring on the Lucie (Freda Peeple)" and Jarvis Cocker declaiming global society's ills with an unprintable refrain in "Running the World," Cuaron emphasizes the timelessness of this future-set film and stamps it with a humanistic double exclamation point.