The conductorless chamber orchestra One Found Sound is celebrating its fifth season by turning each of its concerts into particularly festive occasions. The calendar helped decide what form their concert Friday night would take: Monster Masquerade will include works by Bach (arranged by Webern), Dvorak, and Stravinsky, plus a post-concert dance party. One of the founders of the ensemble, Sarah Bonomo, says costumes are optional, but welcome.

There are more details at the One Found Sound website.

The ensemble makes all of its decisions by consensus, and any player is welcome to make suggestions in the rehearsals to help shape the sound of the performances. The three pieces on this week’s concert at Monument on Ninth Street are the Webern arrangement of the Ricercar from Bach’s Musical Offering, Dvorak’s Wind Serenade, and the Danses Concertantes by Stravinsky. “He never actually intended it to be a dance,” Bonomo explains, “But shortly after he wrote it, somebody choreographed a dance for it, so then it became sort of a makeshift ballet. But it’s not originally intended to be a dance. It has a lot of similarities to Pulcinella, even in instrumentation.” Five seasons in, Bonomo says she and the other founders didn’t know exactly where they would be right now. “When you try to start something of this magnitude, you have this fuzzy idea of what’s far off in the future, but really all you can see is what’s exactly in front of you. Which is good and bad, but I think the best part of that particular way of looking at it is when you get to year five, it feels really good.”

Here’s One Found Sound playing the world premiere of Amethyst, by Eric Choate.