Eternal youth.

Everybody wants it. Millions of people spend billions chasing it. Entire industries are devoted to finding it. Yet nobody has it.

Nobody, expect perhaps the noise-rock titans of Sonic Youth.

After nearly three decades together, their 16th album -- the accurately titled The Eternal -- finds them fundamentally unchanged. Their core lineup remains the same: Guitarists Thurston Moore and Lee Ranaldo, bassist Kim Gordon and drummer Steve Shelley (augmented here by former Pavement bassist Mark Ibold). And their sound remains the same: A potent, raggedly glorious fusion of punk, power, pop, poetry and psychedelia stitched and swirled together from cyclones of dissonant guitar abuse, hypnotically primal rhythms, envelope-shredding arrangements and vocals that wouldn't get any of them past the first four bars of an Idol audition.

This is not to say SY haven't grown up. They spend much of The Eternal looking back and paying tribute to their own influences, from the John Fahey cover art and No Wave sonics to the lyrical nods at Beat poet Gregory Corso and L.A. punk Darby Crash.

But there's a big difference between growing up and growing old. At an age when most of their contemporaries have given up the ghost, SY refuse to coast -- The Eternal marks their return to the indie ranks after nearly two decades in the major-label machine.

And if coming full circle and starting again at the beginning doesn't qualify as eternal youth, what does?

Sacred Trickster 2:11

"I want you to levitate me!" demands Kim while Lee and Thurston slash out dissonant, clanging chords and Steve bashes out propulsive post-hardcore. Welcome back.

Anti-Orgasm 6:08

After Kim and Thurston trade vocals from opposite sides in the mix, the cut builds into a knot of wiry guitars, grunting vocals and pumping tom-toms -- and then mellows out. Go figure.

Leaky Lifeboat (for Gregory Corso) 3:32

Moore, Gordon and Ranaldo gang the mic, fittingly singing, "We got to get it together and row," in a scrappy tribute to Beat poet Corso. Lee and Thurston get slinky on their guitars.

Antenna 6:13

SY can play nice when they want. Here's a midtempo gem with gentle arpeggios, a sleepy vocal from Thurston and a melodic chorus. Even the noisy touches suit the title.

What We Know 3:54

Ranaldo takes the helm for this darkly tense stalker-rocker, slashing out sharp syncopated chords and some guitar-hero riffs while "creeping up and down your block."

Calming the Snake 3:36

It's Kim unleashed again, wailing about wanting to see you shiver and quiver (down at the river, naturally) atop a driving beat and craggy guitars. Short and definitely not sweet.

Poison Arrow 3:43

Picking up where the biting Snake left off, this opens with a minute-plus instrumental buildup before Moore weighs in with a creaky vocal. Lee and Kim join in on the chorus.

Malibu Gas Station 5:39

A dreamy, sparkling intro gives way to a hurried, chugging gait decorated with tremolo-bar guitars and a haunting vocal from Kim. Bonus points for the fake-out ending.

Thunderclap (for Bobby Pyn) 2:39

Thurston salutes late L.A. punk icon Darby Crash of The Germs -- at least we presume "You did not fade from the noise meditation" is a salute -- over a choppy backdrop.

No Way 3:53

The opening riff reminds us of REM -- but it's all SY after that, with Moore moaning about angels and devils and succubi while the band mines a No Wave vein behind him.

Walkin Blue 5:22

Ranaldo gets in touch with his inner hippie, spinning a dose of swirly psychedelic folk-rock straight from the dark underbelly of the '60s. Tune in, turn on and trip out.

Massage the History 9:53

It wouldn't be a Sonic Youth album without a massive shapeshifting epic. Kim handles the ghostly vocals for this one, guiding it from an otherworldly dreamscape to a noisy squall and back.