A month away from joining Radiohead as opener for six dates on its second North American tour leg, indie rock act Grizzly Bear is about to spend the next three weeks in the studio.

A month away from joining Radiohead as opener for six dates on its second North American tour leg, indie rock act Grizzly Bear is about to spend the next three weeks in the studio.

Singer/guitarist Edward Droste tells Billboard.com the new material is sounding more optimistic and poppy than 2006's "Yellow House" (Warp).

"I think we're all in a really poppy place for sure," Droste says. "There are dark lyrics in play, and it's not like the whole album is going to be an up-tempo radio pop thing at all. We'll probably never get played on the radio, but [on] just a couple of the songs the mood is perhaps a bit sunnier than 'Yellow House.'"

He adds, "I think the orchestrations will be equally complex and intricate, but the mood is slightly more a sunny afternoon versus a fall afternoon."

New tracks in the mix include the upbeat "While You Wait for the Others," which the band performed this spring on "Late Night with Conan O'Brien" and is currently offering as a free MP3 download from its Web site.

Also new is the tentatively titled piano-based "Two Weeks." Droste says the track, incorrectly reported to be named "Nine," will be performed on the band's July 23 appearance on "Late Show with David Letterman."

"It's really weird and confusing because it's funny to me we're playing 'Letterman' right now when we have nothing in the stores that's even remotely new," Droste says. "The newest thing would be the EP ('Friend') from last November. So I guess we're doing it just to promote the Radiohead tour. Letterman's people are really psyched about it and happy to have an exclusive."

The band plans on returning to the studio in the fall to mix its next album for a hopeful April 2009 release. In addition, Grizzly Bear songwriter/guitarist Daniel Rossen's side project Department Of Eagles has a new project due in the fall.

As for the Radiohead opening slot, Droste says he's unsure why the band was picked but is nonetheless ecstatic.

"I really feel like -- for me -- it's the ultimate opportunity to be able to tour with Radiohead," Droste says. "Like, it's crazy to me. I grew up listening to them and respect them so much. It's kind of insane. [But] I think we'll be playing to a bunch of people who are getting beer and finding their seats."