Collaboration -- and keyboards -- are the hallmark of Interpol's self-titled fourth album, which is slated for a Sept. 7 release.

"The writing process has always been pretty collaborative, but even moreso this time," drummer Sam Fogarino tells Billboard.com. "I think at the onset everybody was really willing to develop a lot of the ideas that Daniel (Kessler) came up with, and I think everybody was kind of on the same page in terms of direction and where we wanted to take them harmonically and sonically."

He adds that "collaboration is not without impasse and disagreement, but compared to earlier sessions of writing music over the years it seemed like everybody felt a little more secure within their roles in the band and seemed a bit more unified in terms of where we could go musically, and I think it worked. It sounds like Interpol but it'sa little different, which is all you can hope for."

The difference, Fogarino says, is primarily in Interpol's use of keyboards on "Interpol," which he says build on the path set by 2007's "Our Love to Admire" and are more fully integrated into the arrangements. "The little bit of keyboards we used really sit on top of ('Our Love to Admire'), where on this record they found their place," Fogarino explains. "We kind of expanded on the sounds themselves, not just, like, faux orchestral voicings or textures. There was a greater comfort of expanding on those voices and really finding an application for them."

Complicating matters, however, is that bassist Carlos Dengler, who plays keyboards on Interpol's albums, left the band after "Interpol" was recorded. The group hasn't named a permanent replacement -- David Pajo (Tortoise, Yeah Yeah Yeahs, Dead Child) will tour with Interpol while Secret Machines' Brandon Curtis will play keyboards on the road -- and Fogarino says the split with Dengler "very amicable. He's definitely wished well by all of us. He just got tired of being in a band, essentially. It's not what he wanted to do anymore. He has other aspirations, artistically, that he couldn't really embark on. But he was very committed to finish writing and recording ('Interpol'), then he made his exit."

"Interpol"'s release is preceded by the release of a video for the track "Lights," while "Barricade," the first official single, is due out in August. Meanwhile, Interpol -- which was slated to open for U2's postponed North American tour -- has just kicked off a run of North American shows that wraps up Aug. 21 in Miami Beach. The group heads to Europe in September to mix U2 support dates with its own concerts, including an extensive headlining jaunt in November and early December.

Australia is slated for January, and Fogarino says that, "I"m sure we're going to go well into 2011 on this touring cycle."

Here are Interpol's U.S. tour dates:

Oct 18: Oakland, Calif. (Fox Theater)
Oct 21: San Diego, Calif. (Soma)
Oct 22: Las Vegas, Nev. (The Joint)
Oct 23: Los Angeles, Calif. (The Greek)
Oct 25: Denver, Colo. (Ogden Theater)
Oct 27: Dallas, Texas (Palladium)
Oct 28: Austin, Texas (Stubb's)
Oct 29: Houston, Texas (Verizon)
Oct 31: New Orleans, La. (Voodoo Festival)
Nov 01: Atlanta, Ga. (Tabernacle)
Nov 03: Washington D.C. (Constitution Hall)
Nov 04: Philadelphia, Pa. (Tower Theatre)
Nov 05: New York, N.Y. (United Palace)