Sima Cunningham and Macie Stewart, the duo that goes by the moniker Ohmme, were already established musicians in the Chicago music scene when in 2014 they began investigating the idea of creating semi-improvisational, experimental music. While they both play multiple instruments, they focused on taking guitars and vocals into new territory.

“I think we both wanted the freedom and the ability to explore textures outside the usual boundaries,” says Stewart. “It was really cool to play guitars in a way that wasn’t necessarily melodic or harmonic.

While Cunningham and Stewart are intent on shedding their preconceptions about rhythm and exploring all the sounds their guitars can make, they aren’t averse to including a fine harmony and an infusion of pop. It’s a compelling sonic experiment: improvisational rock that’s appealing and satisfying to both novice and seasoned fans.

Jeff Tweedy, Ohmme When: 7 p.m. Aug. 10 Where: Canal Shores, 1030 Central, Evanston Tickets: Sold out Info: evanstonspace.com

“We’re really interested in exploring the tension that exists between something that is sugary pop and something that is totally atonal and messed up,” Stewart explains, “and seeing where those two can intersect and if its possible to do that and what happens when you do.”

Ohmme opens for longtime fan Jeff Tweedy at an outdoor show staged by the Out of Space summer series on Aug. 10 at the Canal Shores Golf Course. In September, they tour with Wilco on a number of European dates. “Ohmme manages to use familiar ingredients and still sound unlike any other band which is an increasingly hard thing to do and an incredibly vital component of a healthy musical environment,” Tweedy says. “They empower other bands and musicians to be themselves and find their own voice.”

Cunningham, 29, and Stewart, 26, are both musical polyglots. They begin studying music at a young age and are both classically trained: Stewart on violin, Cunningham on oboe. In Whitney Young High School, where they both admired each other’s work from afar, Stewart was involved in musical theater and the band Kids These Days; Cunningham played in a popular rock band and sang with the Chicago Children’s Choir. They both were also “kind of secretly playing Irish music as well,” Cunningham adds.

Later, they got to know each other in the fertile Chicago music scene singing backup vocals for Twin Peaks and Chance the Rapper. Cunningham toured with Tweedy, the solo project Jeff Tweedy formed with his son Spencer. They’ve also done string arrangements for both Twin Peaks and the band Whitney.

Chicago has a deep history with experimental music. The Association for the Advancement of Creative Musicians (AACM) was founded here more than 50 years ago. And venues like Constellation and the Hungry Brain, which welcome experimentation, are where Cunningham and Stewart hung out listening and where they later first tested out their own new music.

“There are so many really great improvisers here and it was cool to be exposed to this music on such a high level of musicianship,” Stewart recalls. “We both dove into the improvised scene in a way that is totally disconnected from written material which I feel was important to explore because it informs the way we write and arrange our music. It helps us find all these different textures. It’s about communication more so than making something melodic.”

In 2016, Cunningham and Stewart were added to the roster at the Pitchfork Music Festival and decided to add drummer Matt Carroll to the mix. “It’s an outdoor festival and we thought we needed to add some more energy to the mix,” says Stewart. It turned out to be a good move as things jelled quickly into a trio. “I think it gave us a whole other level of freedom to stretch out and relax into the music,” added Cunningham. “There’s a kind of trinity of communication between the three of us.”

As for the curious band name, their first idea was Homme, French for man.

“There are so many male bands with female references in their name that we thought let’s just call ourselves ‘men,’ ” says Cunningham with a laugh. After learning that name was already taken, they played with rearranging the letters and came up with Ohmme (pronounced ohm).

“We had a list of names and we were facing a deadline to pick a name so we headed over to the Hungry Brain and took a poll of everyone at the bar,” Stewart, recalls with a laugh. “And Ohmme won. This is the one that people liked.”