For the last 11 years, Philadelphia's pioneering five-piece has been at the forefront of spacerock exploration, releasing a string of critically acclaimed albums that blur the lines. Between rock and improvisation. Between structure and chaos. Between songs and jamming. Between harmony and discord. Between music and noise.

THREE OUT OF FIVE: Ticket Crystals completes the trilogy started by 2001's Dilate and 2003's On the Ellipse.

Texture has always been the band's buzzword; their music something you feel as much as you hear, whether with eyes closed at a concert, or with eyes closed between your headphones.

When Isobel Sollenberger, Clint Takeda, Ed Farnsworth and brothers Michael and John Gibbons get together, noise happens. It comes in big cascading sheets of distortion, flute, heavenly vocals and throbbing bass, usually on albums with veiled (or not-so) drug references. So ascribing motive to the band's output, such as the band's just-released ninth long-player, Ticket Crystals (All Tomorrow's Parties) [Listen to Ticket Crystals now!], might seem a tricky proposition.

"It really is all five of us who have input into the overall sound. It's organic amongst us," says Michael Gibbons, the band's guitarist and sort-of de facto leader. "It's not like there's a blueprint. [Our music] is a product of how we are feeling. We record it, listen to it and then we go from there. It's like a sculpture; however it turns out, how we feel in the room, how we feel when we listen to it [influences] what we pick to continue with."

What the band was feeling this time around was lightness. Their last album, 2003's On the Ellipse, was, admits Gibbons, a heavy affair that was directly influenced by the events of 9/11, which happened as the band was starting to work on it. "We were coming out of some heavy solemnity with On the Ellipse. It's still there," says Gibbons of those devastating feelings, "but [Ticket Crystals] is not quite the shock and despair that On the Ellipse was. This one was more exuberant."

Exuberance is a relative term where this band is concerned. But you can hear it in Sollenberger's lilting vocals about constellations on "Isle" and about milder intoxicants on "Moonshine." In the giddy cover of The Beatles' "Cry Baby Cry" (done for a BBC tribute to the Fab Four). In the frantic sampling on "Montana Sacra II." And it's there in the cycling builds and feedback of album-opener "Destroying Angel."

Maybe in Bardo Pond parlance exuberance is another word for freedom. Ticket Crystals sounds like the work of a band with a case of sonic wanderlust, freed to roam, to noodle about a bit again. (For proof of this predilection, visit the band's lovely time-waste of a Web site/toy, www.bardopond.org.)

Part of this exploration is the band's continued but deeper trip into the world of acoustic sounds. "Destroying Angel" starts with 18 seconds of acoustic guitar strumming before the feedback and electric guitars kick in. While the song progresses into an epic series of trademark builds, releases and washes, the intro is no red herring. Ticket Crystals is the band's most in-depth exploration of nonamplified sounds, at least on record, to date.

"We've been saying this record's part of a trilogy that started with Dilate and continued with On the Ellipse," explains Gibbons. "With each part the acoustic investigation has been more processed into the way we work."

Not that acoustic sounds weren't always part of the formula.

"A lot of the music we make, the riffs start on acoustic. John and I would make the songs up on acoustic guitar in the earlier years, and they would wind up as electric presentations," says Gibbons. "Now it's a doorway that looks into the beginnings of the song. It's almost as if the songs are introduced as acoustic and then electric instrumentation comes into the song and progresses from there. It's really been fun. We really like the textures. It's a really nice thing to be part of what we do."

In fact, Gibbons says the band has an all-acoustic project, a sort of reverse Dylan-at-Fairport thing, in mind. "We're going to go for this acoustic psych-folk thing—not to be part of the new weird-America thing—but more like what we were doing with this record, but without the build," he explains.

Gibbons, also a big free jazz fan who likens the band's vibe to Ornette Coleman's tonality theory of harmolodics, says he'd like Bardo Pond to pursue a free jazz project in the future. After all, when you've been playing with the same people for this long (their debut, Bufo Alvarius, came out in 1995, but the band has existed in various permutations starting in 1991), it's important to mix things up. Drummer Ed Farnsworth, who replaced Joe Culver around 1999, will sit out this tour due to school obligations. Jason Kourkounis, a veteran of The Delta 72, Hot Snakes and Burning Brides, has been sitting in for the tour, which has also opened things up a little bit.

"With families you get locked into certain patterns," says Gibbons. "You get more open" when you add someone new to the mix, he figures. "It keeps everybody a little more aware that there's somebody else in the room. It's almost like The Beatles when George Harrison brought Billy Preston in; he just wanted to get somebody in there to lighten things up."

But should fans worry that the Pond's newfound directions will mean an end to the feedback psychedelia of days past? Is the noise dying? Hardly.

"We love fuzz and a little delay," says Gibbons of electronics. "Acoustics are just a different palette, a different mood. Some people don't want to get bludgeoned."

Bardo Pond will play a record release party with Himalaya and Relay, Fri., June 16, 9 p.m., $8, North Star Bar, 27th and Poplar sts., 215-787-0488, www.northstarbar.com.