For a movie that’s been called “the film world’s first globalized masterpiece,” with its gritty portrayal of third-world impoverishment crashing into Western-style modernization and its visceral images of humanity-choked streets, glitzy game show sets, towering mountains of trash butting up against tony condo developments, and self-made men flashing rupees and dollars in brothels and from the back of Mercedes Benzes, Slumdog Millionaire’s music is much more than a soundtrack to a movie; it’s the sound of a city swiftly globalizing. Bollywood meets hip-hop and dirty house meets Bhangra in the frenetic urban scramble that is Mumbai and the whole mix is chewed up and spit out as the everyday cacophony of modernization.

The composer who conjured up this feverish fusion of East and West, traditional and modern, is A.R. Rahman, often referred to as “the Indian Timbaland” because of his characteristic disregard for the confines of culture. Since 1992, Rahman has been redefining India’s widely popular filmi music and he’s worked with a number of international music stars such as Nusrat Fateh Ali Khan, L. Shankar, Apache Indian, and David Byrne. For Slumdog Millionaire he collaborated with another cultural omnivore, M.I.A, who has been big upping Bollywood since her star started to rise a few years ago. Despite the fact that M.I.A.  recorded much of her last album, Kala, at Rahman’s studio in India, the two had never worked together until now. And it’s their collaboration, “O…Saya”, that sets the flurried pace for the rest of the movie.

In the beginning frames, Slumdog’s child protagonists are chased by truncheon-wielding police officers through the slums of Mumbai. As the children race through the alleyways, scurrying around corners, knocking over pottery, and kicking up dirt and dust, “O…Saya” rides in on a chorus of spiraling chant-like vocals and monolithic tribal drums before crescendoing into commotion incarnate. Distorted guitars stomp and children yelp through clouds of synthetic swells while M.I.A. stutter-steps her rhymes in between electronic stabs and jabs. The song and the scene are a perfect marriage of sound and image, conveying the raw realities of Mumbai’s snarling streets, and what’s more — it’s loud.

True to most classic Bollywood films, where the music is front and center, Slumdog’s director, Danny Boyle, keeps Rahman’s soundtrack in the red and in the audience’s face. In an interview with New York Magazine, Rahman says, “What’s good about [Boyle] is that he likes how Indian films mix music. You push it and it comes out. We wanted it edgy, upfront. Normally some directors suppress music — they always want the effects to be loud and the music to be softer. Danny wanted it loud.” And this volume propels the movie, providing momentum and making it physical in spirit, sight, and sound.

During the montage in which the movie’s “slumdog” brothers escape to safety perched on top of a train, M.I.A.’s “Paper Planes” floats and bobs around scenes of the boys stealing their sustenance, the song’s shotgun blasts and cash register rings foreshadowing the protagonists’ next phase in life. As M.I.A. sings “Sometimes I feel sitting on trains / Every stop I get to, I’m clocking that game”, it seems like the scene was written for the song, and it pops up again as a DFA remix — this time with handclaps, booms, rattles and twitters feeding the soundtrack to one of the boys’ many short-lived scams. 

In another scene steamy flutes and seductive Bollywood singers set the tone for a trip through Mumbai’s seedy and sensual red light district, only to give way to other frantic, claustrophobic, chase-driven sounds and rumbling cinematic moments. And all the way Rahman builds up to the film’s jubilant climax, where the Westernized rags-to-riches story closes out with a classic Bollywood-style ending: a choreographed, handclapping sing-along.

In the end (and this is a spoiler alert) the boy wins the money, the boy gets the girl, and the movie ends on an uplifting note. But as you walk out of the movie theater, you’re sure to have Slumdog Millionaire’s sordid images and sounds ringing on your retinas and in your ears — a masterful mix of cinema and sonic vérité that exposes the uncompromising realities of India in the 21st century.