The new Tom Waits album begins, in very Waitsian fashion, with a racket: a squall of percussive noise that sounds like it was recorded in a freight elevator. During the first decade of his career, Waits established a unique persona and a maudlin sound–he was a singing Bukowski, a barfly balladeer who croaked

romantic songs about skid-row characters, accompanied by piano and strings–but starting with Swordfishtrombones (1983), the Beat poet became a poet of the beat, pop’s supreme rhythm freak. He’s filled his records with junkyard percussion and close-miked drums whose sound distorts into a muffled boom. He has pushed lurching, old-time musical machines (pump organ, calliope) to the foreground, reveled in the noise of oddball instruments and found sounds (Swiss bells, glass harmonica, “Indonesian seed pod”) and hired musicians like Marc Ribot, who plays his guitar a bit like a drum–anything to make his songs clatter like a jalopy navigating an unpaved road.

Real Gone, Waits’s nineteenth studio album, brings a new kind of thump. It’s there in that album opener, “Top of the Hill,” alongside a deejay’s turntable scratches and dissonant flashes of electric guitar: a pummeling sound that might easily be mistaken for a computer-generated drumbeat but is in fact the voice of Tom Waits, who borrowed a trick from hip-hop–human beatboxing–and created many of Real Gone‘s rhythm tracks by huffing into a hand-held tape recorder. Waits has long used his voice, one of the most expressive and unlovely instruments in pop, to channel a rogues’ gallery of characters. On the new album, Waits sings both the drunkard’s lament and the sound of his drunken stagger. A voice as loud and leathery as any drum has taken its rightful place in the rhythm orchestra.

Waits’s beatboxing, and the absence of his trademark piano, bring a whiff of novelty to Real Gone. But the album could hardly be called a departure. Waits is still writing taut little poems about love and death and setting them to tunes that distill Kurt Weill, parlor ballads, circus music, rural blues, urban funk, snatches of Afro-Cuban rhythm and other seemingly incompatible source materials. Unlike many veteran performers, who shuffle record producers and hop between trendy styles in an effort to keep up with the zeitgeist, Waits long ago left the world behind; his post-Swordfishtrombones output has been impressively focused, the work of an artist burrowing deeper into his eccentricities. Despite minor shifts in tone and texture, it’s fair to say that Waits has been making the same album for the past twenty-two years.

Of course, no one but Waits has been making that album; he’s a genre unto himself. Who besides Waits could dream up “Metropolitan Glide,” which slows a James Brown groove to a sinister creep, adds some raggedy guitar picking and serves up a string of Bizarro World dance-floor instructions: “Turn off the sound on your cellular phone/Whip the air like a Rainbow Trout…Show your teeth bray like a calf”? That song, like most on Real Gone, is swamped in noise: feedback, overloaded microphones, fuzzy guitars. It’s a sound as thick and lumpy as a bowl of goulash, and listening to it you realize how accustomed your ears have become to the crispness of digital-age pop; of all Waits’s perversions, none are more refreshing than his devotion to sonic muck. The mambo-blues song “Shake It” takes the approach to an extreme, setting Waits’s lead vocal against Ribot’s lead guitar and gradually ratcheting up the distortion on both, until it’s nearly impossible to tell one from the other.

If Waits’s music makes a virtue of clutter, his lyrics have an almost classical tidiness. (He’s one of the few rock songwriters whose words read well on the printed page.) On Real Gone, the songs are bleak and blood-soaked; Waits may be reacting to world events–the album includes at least one explicit antiwar number, “Day After Tomorrow”–but as always, his songs seem to float outside time, pieced together from old books, old movies and other scraps of cultural memory. In recent years Waits has gone rustic, leaving behind the diners and dive bars of his early albums to lay his songs in stark rural settings. Most of the songs on Real Gone take place in a kind of Gothic Upper Midwest, a landscape of cornfields, slate-gray skies and violence. In “How’s It Gonna End” Waits sings:

The barn leaned over The vultures dried their wings The moon climbed up an empty sky The sun sank down behind the tree on the hill There’s a killer and he’s coming Thru the rye

Not just anyone could get away with lines like these. Waits’s voice, which even at its most dulcet sounds like a revving lawn-mower engine, is his secret weapon: It allows him to sing things that would sound corny coming from anyone else. And yet, while his art depends utterly on his singing, it’s his singing–the shamelessly overwrought manner in which he tries on the voices of hobos, old salts, carnival barkers, madmen–that gives a listener pause. Several years ago, a friend walked out midway through a screening of Waits’s 1988 concert film, Big Time. He’d been repelled by Waits’s bug-eyed stage antics and by a voice that seemed to grow more cartoonish with every song. “It seemed almost like minstrelsy,” my friend said.

He wasn’t wrong. Waits is filed in the rock bin at your local record store, but his soul belongs to the musical theater–not the tradition of Sondheim or even Brecht and Weill but that of Joe Weber and Lew Fields: the primitive and unruly turn-of-the-century vaudeville stage, with its ethnic dialect singers, blackface comedians and sentimental balladeers bellowing Tin Pan Alley tunes to the cheap seats. Today, we are uncomfortable with this colorful, complicated, vulgar part of our musical heritage, but it remains one of the seedbeds of American song, and Waits draws on it avidly, embracing vaudeville-style coarseness and artifice in a musical age obsessed with authenticity. Listen to virtually any rock singer, and you’ll hear variations on a single persona: sensitive rocker, sexy rocker, gruff rocker. On Real Gone, Waits roars like a pirate in one song and slurs his words like a drunk in the next; he sings in the voices of a 21-year-old soldier, a circus performer, a cuckold, an escaped convict and a dead man. It’s postmodern minstrelsy of a very high order.

But the roots of Waits’s music stretch deeper into the past. His wife, co-producer and frequent collaborator, Kathleen Brennan, has described her husband’s two songwriting modes as “Grim Reapers and grand weepers,” themes that link Waits’s work not only to that perennial rock-and-roll wellspring, the blues, but to some of the earliest American pop songs: to death-haunted Victorian ballads, with their tragic loves and waltz-time melodies, and further back, to nostalgia-soaked antebellum parlor songs. We can hear echoes of those ancient songs on Real Gone: in the spooky “Green Grass,” sung by a ghost to the lover at his graveside (“There’s a bubble of me/And it’s floating in thee”); in “Sins of my Father,” with its pastoral scenes and dream of “Jenny with the light brown hair.” Forget punk revivalists, with their haircuts and snarling three-chord songs straight out of 1977; forget Lenny Kravitz, with his flared pants and vintage tube amplifiers. Tom Waits is keeping Stephen Foster’s nineteenth century alive in twenty-first-century pop. Now that’s a retro-rocker.

Waits has an unlikely spiritual cousin in Björk, the little Icelandic sprinkler of musical fairy dust whose new album was released a few weeks back. Like Waits, Björk is a pop singer-composer-producer with a tenacious avant-garde streak; like Waits, she’s a romantic, a creator of her own beautiful and idiosyncratic grand weepers. And now, in the same season that has brought us Waits’s debut as a vocal percussionist, Björk has delivered Medúlla, on which she’s abandoned instruments almost entirely, gathered a motley group of vocalists–hip-hop beatboxers; rock singers of various stripes; an Inuit throat singer; a “human trombonist”; and two choirs–and paid extravagant tribute to the power of the human voice.

Medúlla is not exactly unprecedented. From barbershop quartets to gospel close-harmony groups to doo-wop to the kooky a cappella experiments of Todd Rundgren to Bobby McFerrin’s novelty hits, vocals-only pop music has a long history. But the scale and ambition of Medúlla is something different–“Don’t Worry, Be Happy” it ain’t. Björk has continually shoved at the edges of pop song form, embracing the skittering beats and digital white noise of cutting-edge electronica, scoring tunes for laptop and string octet, pushing her songs toward the grandeur and abstraction of contemporary classical music. On Medúlla Björk and a team of producers–Mark Bell, Valgeir Sigurdsson, who has worked with Icelandic group Múm, the San Francisco-based experimental duo Matmos–move further afield, crafting what amount to a cappella mini-symphonies. Even Björk’s most devoted fans, who relish her odd juxtapositions, may find themselves bewildered by songs that hover somewhere between Le Mystère des Voix Bulgares, Meredith Monk and ambient techno.

Certainly, there’s never been a pop tune quite like “Where Is the Line,” which dangles Björk’s lead vocal melody between a rubbery beat and the dissonant drone of the Icelandic Choir. Midway through, the choir breaks into an eerie whistle; several phantom Björks surface via the magic of multitracking, echoing the vocal line and dissolving in a haze of radio static; and human trombonist Gregory Purnhagen, punk singer Mike Patton and the virtuoso human beatboxer Rahzel layer on grunts and growls that ricochet across the stereo spectrum.

Other songs are even weirder. “Sonnets/Unrealities XI” pairs Björk with the Icelandic Choir in a plainchant setting of an e.e. cummings poem–call it Gregorian Pop. “Ancestors,” one of the few tunes to add extra instrumentation, finds Björk singing a stately melody–in lyrics that might be English, Icelandic or just plain gibberish–backed by a few stray piano chords and the quavering cries of throat-singer Tanya Tagaq.

It’s tempting to dismiss Medúlla as a pretentious stunt. Björk is a famously artsy-fartsy pop star–a darling of the Whitney Biennial set, the girlfriend of artist Matthew Barney, the star of Lars von Trier’s Dancer in the Dark, an avant-garde fashion plate who turned up at the 2001 Oscars swaddled in a swan carcass, looking like a walking Damien Hirst installation. In a Rolling Stone interview before the release of Medúlla, she announced, “Instruments are so over,” an idea that might play well in the Scandinavian salons that brought us the Dogme 95 film movement but sounds silly down here on planet Earth.

A song like “Triumph of a Heart” does little to dispel the skepticism. It’s a catchy, propulsive dance tune, reminiscent of several earlier Björk club anthems, in which Rahzel and an amazing Japanese beatboxer named Dokaka replicate the 4/4 bump of a house-music track. In fact, the beatboxers do such an astonishing job of mimicking the sound of a kick drum and various accompanying electronic squiggles and beeps, you can’t help but ask: What’s the point? In the past, Björk has made gorgeous dance music by sampling and looping computers that impersonate instruments; here, she makes gorgeous dance music by sampling and looping singers impersonating computers that impersonate instruments. It’s a neat trick, but why bother paying for the plane flights and studio time when you can boot up your laptop and get the same result? At such moments, Medúlla seems like something rather more mundane than the herald of a post-instrumental new musical order: Björk Unplugged.

But on further listening–close listening–the album begins to open itself up to you. The man-as-machine verisimilitude of the beatboxers is gimmicky, but Medúlla teems with other, strange and beautiful sounds that can only be produced by vocal chords crammed into traditional verse-chorus pop songs and spread across sprawling abstract pieces, chopped up and reconfigured like dance tracks. The album’s centerpiece is “Oceania,” a ravishing song written for the opening ceremony of the Athens Summer Olympics, in which Björk sings in the voice of “Mother Oceania,” cooing comfort to her “little ones”: islands and continents. “Oceania” features a gritty lead vocal, but the song’s tour de force is the arrangement Björk has composed for the London Choir, a gloriously burnished version of haunted house music–swooping, rising and descending scales, the sound of a ship being pitched on ocean swells.

Rock journalists frequently refer to Björk as a “pixie”–and to be sure, this tiny woman with twinkling, almond-shaped eyes and a funny accent has an air of the enchanted wood-sprite about her. But no one who has heard Björk’s grand, growling signature songs like “Hyper-Ballad” or “Joga” can doubt that she’s a diva–not a modern-day ice queen diva like Madonna but a red-blooded diva in the Piaf-Callas-Billie Holiday mode, a fearless emotional exhibitionist who stuffs and mounts her joy and pain in song after song. Many of Björk’s best moments are almost too personal to bear. “Pagan Poetry,” from Vespertine (2001), builds slowly, with Björk wailing over swelling keyboard crescendos–“The darkest pit in me/It’s pagan poetry…. He makes me want to hurt myself again”–until, at the song’s four-minute mark, all the music drops away, leaving Björk utterly exposed: “I love him, I love him/I love him, I love him/I love him, I love him/I love him, I love him,” she sings.

With Medúlla, Björk reaches a new milestone in her journey inward. Since launching her solo career in 1993 (she had been a singer in a post-punk guitar band, the Sugarcubes), she has continually sought more spartan settings for her songs, progressing from extroverted dance music through increasingly austere forms of techno. “Medulla” is Latin for marrow, and the record, stripped of nearly everything besides vocals, is an attempt at the deepest kind of unmediated musical expression–fitting for songs that reach beneath the skin and inside the bones.

But Medúlla‘s most startling moments of emotional nakedness aren’t “Pagan Poetry”-style flights; they’re not even especially musical. They’re little sonic details, buried deep in Medúlla‘s mix, some detectable only through a good pair of headphones: In “Pleasure Is All Mine,” the sound of heavy panting, panned to the left of the stereo spectrum, and a gulping, swallowing sound in the far-right channel; elsewhere, stifled sobs, contented sighs, rasps, mewlings, a cry that sounds like a woman in childbirth and the most basic voice-music of all, the flutter and rush of indrawn and exhaled breath. These bewitching, unsettling sounds point beyond Björk’s own universe of love and pain to the pleasantly utopian idea that even the tone-deaf among us are singers, that wherever there is a pair of lungs there is a kind of music. The most erotic lyrics you’ll hear this year aren’t about sex, they’re Björk’s paean to the mechanics of breathing in “Triumph of a Heart”: “Smooth soft red velvety lungs/Are pushing a network of oxygen joyfully/Through a nose, through a mouth.”