M.I.A.’s first album, Arular, had a song called “10 Dollar”; her new one, Kala, has “20 Dollar.” That’s one measure of where she stands now. M.I.A. is no longer the startlingly exotic, smart new girl; she’s started a pop career. Now the world, or at least anyone who cares, knows about the Sri Lankan-English rapper-singer-chanter who matter-of-factly juggles politics, swagger and nonsense syllables over beats that jab and zap. The bombshell that was 2005’s Arular used a cheap hip-hop beat box and sounded homemade. Kala, by contrast, was recorded in studios around the world. Though M.I.A. has kept the tracks stripped-down, Kala sounds slightly less brittle and one notch less hyperactive than Arular, as if she now wants to save a few ideas for later. But Kala is still exactly what she calls it in the album’s first song: a “Bamboo Banga.”

M.I.A., whose full name is Maya Arulpragasam, remains a bundle of First World–Third World paradoxes: an art-school graduate and a refugee from civil war; a pop hottie; and a revolutionary sympathizer. “Hands up, guns out, represent the world town,” she chants.

M.I.A. knows one thing for certain: The best beats come from the poorest people, and even from the comfort of her digs in Brooklyn, she identifies with them. Splinters of manifesto poke through her lyrics: “Dancing as we’re shooting up and looting just to get by,” she singsongs in “20 Dollar,” over a rhythm track that includes a gunshot. It’s not the only one; in “Paper Planes,” which by M.I.A. standards is almost a ballad, she lilts, “All I wanna do is [gunshots: BANG BANG BANG BANG] and [cash register: KA-CHING!] take your money.”

Yet the impact of M.I.A.’s music isn’t in what she says, but how it arrives: in tracks so irritating they’re irresistible. Anything but naive, M.I.A. brings a connoisseur’s ear to her beats: the boops and buzzes of electro, distortion from London grime, hand drums from Indian Bhangra, nasal Bollywood hooks, bass lines from Jamaica, Miami and Brazil — even a nod to a recent Ivory Coast dance craze, “BirdFlu.” (She has also discovered far-off Boston, with songs on Kala that quote the Modern Lovers and Pixies.)

M.I.A. is definitely an art-school collagist, but one so noisy, assertive and danceable that there’s no stopping her. Her basic recipe for the tracks on Kala mixes drums (real and artificial), sneering hornlike hooks and every vocal tone she can devise, arriving from every direction. “XR2” starts with what might be a muffled dancehall beat, overlays it with a shallow, stuttering drum machine and fake hand claps, then pokes against the beat with a synthesizer line that merges fanfare and Morse code. The rest is her voice, calmly unsyncopated while the track ricochets all around her.

“Boyz” turns M.I.A. into a troupe of chanting, nattering women while drums sputter, synthesizers swoop and crowd noise whooshes in. “Hussel” has her cooing and rapping amid jungle noises and heavy breathing. Kala is that rare album where a Timbaland track — “Come Around” — sounds almost conservative.

Now that the joyful shock of Arular has eased, M.I.A. is probably bound for a backlash. How dare she claim to represent the war-zone casualties, the shantytown poor, the subsistence-level hustlers? Who gave her the right to use that Brazilian baile funk or those Bhangra drums? Isn’t she just another pop poseur? The answer is that she’s entitled because she’s willing to raise those questions at all, and because her tracks hit home on the most visceral level. Pop is full of posturing, and M.I.A., turning Third World devastation into a hard-nosed party, has come up with a pose worth pursuing.
Download: “BirdFlu,” “Paper Planes,” “20 Dollar”