James Singleton formed the Illuminasti Trio with saxophonist Skerik and percussionist Mike Dillon after Hurricane Katrina. “It was very informal, just improvising,” he says. “We discovered a great common ground for our improvisations and took it from there.”

The Illuminasti Orchestra, which descended from the original trio, will perform tonight at 9 p.m. at the Big Top. The ensemble will include three great local improvisers: saxophonist Tim Green, trombonist Rick Trolsen, and guitarist Chris Alford. “This band deals with many textures and styles with an orchestral array of sounds,” says Singleton. “Every participant is a great player and a great improviser and a great composer.”

Singleton hopes to create something new with this combination of artists. “The trio is established in a way, although it’s constantly expanding,” he says. “I thought it would be fun to add three other voices that are very different but also very established and see what happens.”

In addition to the performance, Singleton has a few recording projects in the works that he hopes to release later in the year. “I’m trying to finish up a James Singleton Quartet record,” he says. “We have it about 70 percent done. I think we’re going to end up with enough material to finish my record and start and/or finish an Illuminasti Trio record.” The Illuminasti Trio will also perform this weekend, Saturday night at the Blue Nile and Sunday at Snug Harbor.

The group will perform some composed material, but the focus remains on improvisation. “For many years, with my band 3Now4, we got in the habit of always doing an improvised piece first. That way, you’re instantly on the same level with the audience. And no one in the room knows what’s going to happen.”