Much of Portishead's third album comes down to what it is not. Geoff Barrow, the mastermind behind the British trio, acidly observed that in the wake of trip-hop's mid-'90s ascendance, Portishead's scratchy, introverted anthems were turned "into a fondue set," their late-night ambience appropriated by advertisers. Easy as it might have been to turn in another Dummy (nearly 15 years after its canonization as a seminal trip-hop text), Barrow, guitarist Adrian Utley, and singer Beth Gibbons fashion a new sound on Third. The results are mixed and most likely won't be used to sell fondue sets — or anything else, for that matter. The record took a decade to make, and it takes more than a few listens to absorb its new appropriations: clanging krautrock guitars, surprisingly aggressive beats, catchy electropop. And even though some of the new songs stretch Gibbons' delicate voice to its brink, Third offers a throughline to Portishead's spooky roots, as do the spectral, minor-key melodies. The album's closing cuts reconcile the group's new sound with its classic one. Over a muscular groove enhanced by cowbell (!) and free-jazz sax, "Magic Doors" includes an irresistibly gloomy chorus and some familiar lyrical sour times. The even bleaker "Threads" queasily builds to a roiling rock chorus while Gibbons wails, "I'm always so unsure." You don't get much more '90s than that.