When musicians from popular rock bands start turning up in avant-garde art spaces to show off their solo projects, it can be a dubious proposition. But that won’t be a concern when Glenn Kotche and Bryce Dessner share a stage this week at the Manhattan performance space the Kitchen, taking a creative respite from their duties as the drummer for Wilco and the guitarist for the National, respectively.

Both players have long been invested in their own composing, which fits loosely into contemporary music formats and predates both Mr. Kotche’s employment in the eclectic, alt-country Chicago outfit and the breakthrough success Mr. Dessner has enjoyed with his Brooklyn-based group, whose 2007 album “The Boxer” made several high-profile Top 10 lists.

“There’s a spillover,” Mr. Kotche said of his various musical outlets, calling from a tour stop in Washington, D.C. “These things definitely all inform each other. There’s a balance for me. I can’t imagine one without the other. I wouldn’t be complete.” The percussionist, who released his solo album “Mobile” (Nonesuch) in 2006, will perform Thursday and Friday, and will likely feature selections by Steven Reich, Joao Gilberto, and Max Roach, and introduce a new piece he wrote for Kronos Quartet. He’ll also enlist in a 17-piece ensemble that will perform a new piece by Mr. Dessner, who is tapping into the same pool of indie-rock and classical players that recently accompanied the songwriter Sufjan Stevens in the premiere of his “BQE” at the Brooklyn Academy of Music. Mr. Stevens will be there, too, in a sideman role.

“I want to push the boundaries a little harder,” Mr. Dessner, back home for a brief spell after extensive touring, said. “I go to a lot of contemporary music concerts these days and people are barely playing. They use a lot of tape loops and electronics. This is going to be more traditional in a way.”

Like Mr. Kotche, the guitarist does most of his writing on the road, “in 40 different cities,” between sound checks and afterparties. But it’s become more challenging since the band’s profile rocketed. “All of our lives have been transformed,” he said. “It’s nice to have something that is really, purely for my own creative enjoyment.”

Mr. Dessner first met Mr. Kotche in 2004 and quickly invited him to play in his Music Now festival, a new-music gathering that the guitarist organizes and promotes in his native Cincinnati, Ohio. The pair have talked about collaborating for a long time. “I love playing in the National,” said Mr. Dessner, who formed the group with his brother Aaron and three friends, in 1999. “It’s not about the grandstanding of any one person. It’s really democratic, but you never totally get what you want, and it can be really frustrating if that’s all you’re doing.”

The gap between serious chamber music and amplified rock ‘n’ roll has been collapsing since the mid-1960s, when the viola player John Cale slipped out of minimalist godfather La Monte Young’s orbit and joined the Velvet Underground. More recently, organizations such as Bang on a Can have erected a giant circus tent roomy enough to accommodate any genre that sparks creative thinking about music. Bands such as Radiohead — and, in its more experimental phases, Wilco — have steadily mutated away from their “alt-y” origins, even while staying true enough to verse-chorus-verse not to dither into sheer abstraction.

Mr. Kotche, for one, is happy to see traffic moving in both directions. “Little shows like this are hopefully helpful,” he said. “It’s good to alert fans that there’s a lot of interesting music that’s not just at rock and jazz clubs.”

Mr. Dessner’s ensemble piece, which will be accompanied by a short film by the artist Matthew Ritchie, has been shaped to flow along with the visual element, and vice versa. Among several other brand-new pieces, Mr. Dessner will present a guitar duo written with his brother in mind. “It’s called ‘Jumeaux,’ and we each play the same piece but one eighth-note out from each other,” he said. “I feel like the country hack,” he added, noting that the program follows a recent concert by the contemporary wunderkind Nico Muhly in the same series at the Kitchen. “But I’ve carefully created each measure, like a folk artist creating a little sculpture. It’s basically handmade.”

Messrs. Kotche and Dessner will perform Thursday and Friday at the Kitchen (512 W. 19th St., between Tenth and Eleventh avenues, 212-255-5793).