Aaron Pillar, guitarist for The Appleseed Cast, is a self-proclaimed geek.

His geeky tendencies don’t manifest in a stereotypical way, though. Pillar simply has heavy interest in anything that produces an intriguing sound.

“If we can get our hands on something that makes really cool noises, we’ll start playing with it,” Pillar said. “We love whatever toys we can play with.”

Sagarmatha, which translates to Mount Everest in Nepali, explores that sentiment to a degree The Appleseed Cast’s previous releases have not.

A song such as “Like a Locus” features synthesizers in the background and foreground and is carried by a pre-programmed drumbeat. True to form, nearly every song is coated with piles of guitar-pedal and studio effects.

The album also marks a return to the post-rock and instrumental leanings more prevalent on 2001’s Low Level Owl series, where some song lengths didn’t hesitate to cross the six-minute mark and vocals were notably sparse.

The band will bring its live show to DC9 in Washington on Tuesday. Pillar said he enjoys performing the band’s longer tracks in a live format.

“They’re a lot of fun to play,” he said. “You have more time to tell a story. You’re not rushing.”

Lengthier, multi-movement songs also lend a more dynamic spin to the performance, which Pillar described as “loud, aggressive, dissonant at times and a little improvisational at times.”

On Sagarmatha, vocals take a definite backseat to the music. A handful of songs on the album are fully instrumental, such as opener “As the Little Things Go,” which only features vocals on the last two minutes of its eight-minute running time. When Chris Crisci’s voice does appear, it comes drenched in effects.

“We always use the voice as an instrument,” Pillar said. “We never wrote songs on [Sagarmatha] from the standpoint of the vocals but always like another instrument that gets added in later.”

That isn’t to say The Appleseed Cast is on its way to phasing out singing altogether.

“There’s no reason why the next record won’t be three-minute-long happy songs,” Pillar laughed.

As it stands, Sagarmatha functions as a travelogue through the recent history of instrumental and post-rock music. There are twinkling, Explosions in the Sky-style guitars, bits of exploration into the realm of electronica (most notably on certain drum tracks) and massive climaxes. Most songs are filtered through a mass of reverb, delay, distortion and other effects.

“One Reminder, an Empty Room” is the exception, a tender two-minute interlude based largely around a pair of acoustic guitars. Pillar noted how the song was an impromptu recording created with one microphone in a garage in the middle of the Sagarmatha sessions.

“It was just something that we were playing with at home, but it has a kind of cool feel,” he said. He added that most of the instrumental parts – guitar, xylophone, bells – were done in one take.

With the release of Sagarmatha, critics are beginning to place the band under the post-rock umbrella. In the late ’90s, the band’s label was emo in the vein of Mineral and Sunny Day Real Estate, and in past years, it has been a melding of that and indie-rock.

Pillar believes the music his band creates falls into none of the above categories.

“We’re certainly trying not to fit into any genre,” he said.

He stumbled for an adequate definition before settling on The Appleseed Cast as a “rock and roll slash art rock” group.

But even then, conforming to such overarching labels did not sit well.

“Our concept of a record idea is that a record should always be a piece of work, a piece of art,” he said. “We’re not going to limit ourselves to what we’ll do on a record.”

The Appleseed Cast will be performing with An Horse and Solar Powered Sun Destroyer on Tuesday at DC9. Tickets are $12 and doors open at 7:30 p.m.

jwolper@umd.edu