By Peter Valelly

Portishead’s new album “Third,” out April 28, somehow seemed destined to fail, hopelessly uncool and totally out-of-place. Sure, the Bristol, UK group’s 1994 debut “Dummy” has long been canonized as one of the great albums of the ’90s. But its ostensible genre, “trip-hop,” has largely been recognized as the sonically turgid and poorly named fraud that it was. Meanwhile, the group’s underwhelming self-titled second album was released in 1997, leaving a decade-long gap in their studio output.In October, in the shadow of Radiohead’s monstrous “In Rainbows” charade, Portishead announced that their third studio album, called simply “Third,” would be released in 2008. The news seemed to come long after the band’s listening audience had forgotten they existed. Indeed, here was a comeback that pretty much no one was asking for.

Improbably, then, “Third” is a triumph. Rather than rehash the morose “Dummy,” the new record accelerates and intensifies that album’s emotional pain. At points, the record seems so trenchantly melodramatic that it eclipses and escapes the actual range of human emotion.

While singer Beth Gibbons’ choked, fraught vocals play a part, this surreal and feverish tone is particularly established by the album’s awesomely inorganic sonic architecture. On cavernous single “Machine Gun,” the sound is something like ’80s industrial via dubstep, a childhood nightmare surgically assembled from the most doom-laden sounds available. Amid punitive synth drums and Gibbons’ wailing, the song’s mid-range frequencies splinter and shred the way that bass sounds tend to do on shitty headphones. The sonically startling track is one of many on the album that tease and dodge conventional notions of genre – a quality that music desperately needs in 2008.

Album opener “Silence” brims with similar invention. Its rolling and crackling rhythms grind away in the bass registers, seemingly detached from the static-drenched swaths of strings. Gibbons’ vocals are particularly harsh here, so closely recorded that every consonant sound hisses. The melody is lovely and laden with agony as the song builds to its dissonant conclusion.

“Hunter,” meanwhile, is wrought alternately from steady beauty and from roaring distortion. It’s one of many delicate, forgettable tracks which seem strategically placed to set up the album’s uneasy climaxes. “We Carry On,” for example, is nauseous and harsh – not to mention spiked with an atonal guitar solo so abrupt that, on my first listen, I thought someone had put on another CD simultaneously – but somehow seems more of a mood piece than a masterpiece. The short, mostly acoustic “Deep Water” is interrupted with strange choral moments, making it from a folk song into something slightly off-kilter.

Rivaling “Machine Gun” as the album’s finest moment, however, is “Nylon Smile.” With muted but tom-heavy percussion and synth whimpers that seem to perpetually recede from the aural environment, the song suggests a ghostly feminine counterpart to Radiohead’s “There There.” In the middle of it all is Gibbons, her soprano razor sharp and her words harrowing. The song begins with fluid cooing before the lyrics frame a paranoid depressive trapped in her own doubts. On the chorus, she issues an impossibly self-loathing lovers’ plea: “I don’t know what I’ve done to deserve you/ And I don’t know what I’d do without you.”

Of course, an album this dark can hardly sustain a sane listener’s full attention, and “Third” becomes dreary as it goes on. The album finally careens to a close with “Magic Doors,” whose combination of drones and askew rhythms is almost dizzying, and the final track, “Threads,” which is so slow it feels on the verge of unraveling until its terrifying and captivating climax.

It’s a surprise to see Portishead of all groups bringing us some of the freshest music of 2008. Some might even take it as a sign of desperate musical times that we’re looking for musical innovation from a band whose coffee-shop-tinged gloom has long been passé. Yet there’s something uniquely captivating and enthralling in the artificially heightened emotional gravitas of Portishead’s latest. Ultimately, there’s even a surprising hint of hope; who knew a band could reemerge after such a lengthy silence? It’s enough to make me wonder what other improbable comebacks are waiting in the wings.