After a 10-year hiatus, Portishead is back. This is an energized reboot, with the aptly titled "Third," a record bristling with angst, darkness and a desire to obliterate misperceptions of the band as merely hip background music.

"We've always had to struggle with that kind of thing," said Geoff Barrow, the 36-year-old founder of the band, which he named after the English coastal town where he once lived. "When our music absorbed into the mainstream, a lot of people started thinking that it was like a chill record or that sort of thing. But we've never really ever been about that."

In 1991, Portishead formed in Bristol, fusing Barrow's turntable skills, Adrian Utley's jazz guitar background and Beth Gibbons' haunting, fragile voice. At the time, Bristol was becoming a "scene" that also birthed Massive Attack, Tricky and a moody, electronic sound dubbed trip-hop (a term Portishead dislikes).

With classic dirges like "Mysterons" and "Glory Box," the trio became a band with whom no college student was unfamiliar. Having carved out a distinct space, "Portishead" morphed into an adjective lent to hundreds of music reviews.

The narrowing view of Portishead wasn't lost on the band. And after a large festival tour and a lavish 1998 live album performed with the New York Philharmonic, the group felt they were clouded by excess.

"We burnt ourselves out in '98," said Utley, 51. "It's the reason we weren't interested in doing Portishead because we just absolutely went too much."

The 43-year-old Gibbons, who hasn't given interviews for years, released a solo album in 2002 ("Out of Season") with Talk Talk bassist Paul Webb. Utley contributed to the album, toured with Gibbons and spent time working on various soundtracks.

Barrow retreated to Australia, where he set up an experimental label, Invada, and produced for the band The Coral, on which Utley also worked. Both Barrow and Utley went through divorces.

"At the end of our (1998) tour, I kind of thought we had actually fulfilled our musical life," said Barrow. "Not like it was over — we would never quit — but we really had to go away and think how we did stuff. That took six years before we could comfortably get back together and say, 'We've got a cause now.' "

Barrow says he entirely quit music for three years, that he didn't "have it in my stomach." Inspiration returned after Barrow listened to bands such as Sunn O))) (pronounced simply "sun") and Ohm, as well as watching bands on his label — "brilliant people with no commercial aspirations," he said.

The group tried to put some music together in 2001, but failed to produce anything exciting. They reconvened in 2003, when Barrow and Gibbons recorded "Magic Doors," one of the 11 songs on "Third."

"We always had an idea about what we wanted," said Utley. "We didn't want it to sound like old Portishead — 'Glory Box' or 'Cowboys' or anything. But we do reference our own albums in spirit."

He added: "We were more interested in dissonance, darker, colder sounds. We talked about that a lot."

Still, once back in the studio, the going was slow. Portishead has always chosen to work long and hard to build their textures precisely. "Third" took about four years to complete, a process Barrow said was "just pulling teeth."

"I'm not really the person that wants to go 'Yeah!' when you hear a guitar solo," Barrow said. "I run in the opposite direction."

The most emblematic song on "Third" — and surely a sprint away from stylishness or bravado — is "Machine Gun." Purposefully abrasive — far more so than the Jimi Hendrix tune by the same name — the song uses drum machines to mimic the sound of a machine gun.

Sings Gibbons: "I can't see nothing good/ Nothing is so bad/ I never had a chance to explain/ Exactly what I meant."

Barrow said he doesn't see any great departure in the new material and believes their earlier work was just as dark: "To me there's no difference between ('Machine Gun') and 'Wandering Star.' "

So far, the album has been met with largely glowing reviews. Said Spin magazine: "Instead of revisiting the past, Portishead capture the present's anxieties."

The band members says they feel rejuvenated. "Third" closes out their record contract with Universal Music Group, and both Utley and Barrow say that's a liberating feeling.

"We feel like we're in the same place, just progressing," Barrow said. "We just want to keep on working. I'm definitely re-energized. I think we all are."

Learn more: www.portishead.co.uk