The high-pitched tinkling of a Mister Softee truck’s melody wafted through the street-level entrance to dance company Cedar Lake’s Chelsea studios during a recent rehearsal. The company’s strapping dancers, many in midstride, acknowledged its familiar refrain, but ever so slightly — a raised eyebrow here, a slight smirk there. They knew better than to pay it much heed.

Ice cream jingles, after all, will be the least of their disruptions tomorrow when this contemporary ballet company begins a second season of its innovative performance series “3 Thursdays.” Equal parts choreographed dance performance, collaborative theatrical work, and interactive installation, the series bridges the gap between dancer and audience by merging the two in the most physical sense.

Though the new incarnation of the show contains different choreographic material than previous ventures, the project’s most significant element remains the same: Viewers are invited, free of charge, to wander through the company’s temporarily gutted theater while dancers perform within the crowd, plunging through the audience in an athletic duet, or executing dynamic steps within inches of wide-eyed lookers-on. “It’s kind of like a laboratory,” Cedar Lake’s artistic director, Benoit-Swan Pouffer, said. “You see them sweat … they become more reachable, more like human beings. You’re involved with the work, you’re part of the work.”

While much of the choreography and direction is predetermined, the course of the shows depends somewhat on the fluctuations of the crowd. “It’s not ‘Okay, here’s my quarter-mark,'” Mr. Pouffer said. “Because a few people might be on your quarter-mark — what are you going to do? That’s the idea.”

For dancers, the show’s format poses unusual and sometimes physically demanding challenges. “It gives you limits, and then it takes them away,” dancer Jason Kittelberger said. “You heighten your awareness. If you’re used to using all the space, all of a sudden your brain has to think and you have to figure out how not to travel each step. It challenges your brain.”

Heather Hamilton, a muscular redhead sitting nearby, nodded vigorously. “The stage is usually our boundary. That is where we create space,” she said. “This time, the people were our boundary, so they were creating our space.”

For Ms. Hamilton, interacting with the crowd was also a test of wills. “Some people did … not … move,” she said melodramatically. “Sometimes I would give them a little advice: ‘It’s best to step back right now,'” she said, demonstrating in a loud whisper. “Sometimes they would think we were confronting them, so they would be like, ‘I have to stand my ground,'” Ms. Hamilton said. “So they actually became part of the dance.”

The series began as a run of three performances this past July, organized on Thursdays to coincide with Chelsea gallery openings that typically occur that day of the week. When crowds grew to 400 people and lines stretched toward the western end of 26th street from the company’s midblock studios, Cedar Lake extended the run for another month.

The show’s previous incarnation featured a series of vignettes linked by tenuous stylistic threads, and was choreographed by various members of both the Cedar Lake artistic staff and its dancers. The new version is more cohesive. Mr. Pouffer supplied most of the choreography, inspired by his reflections on “The Last Supper” (complete with a 16-foot-long rectangular table on which the dancers perform), and other preplanned performance elements like video projection.

But an improvisational feel and outré elements remain. Dancers scale the theater walls aided by a series of pegs, and at times perform wearing large plastic dental guards that prop open their mouths to expose their teeth and gums. During a recent rehearsal, Mr. Kittelberger and another dancer practiced a scene in which the two perform atop the theater’s bathrooms (which are constructed like boxes that stop short of the theater’s ceilings), temporarily trapping anyone who happens to be inside at the time.

Mr. Pouffer said he allowed the dynamics he observed during the previous “3 Thursdays” shows to dictate the direction of the new work. “I was really fascinated by the people moving in a group. There were always a few lingering in the back.” While the summertime shows were comprised of short solos or duets performed around the theater in succession, allowing viewers to watch one piece after another, tomorrow’s performance will operate differently. “This time you have to make a decision. You have to choose what you want to watch,” Mr. Pouffer said. “Before it was: Look here, look there, and then everybody walk over here,”he said. “This time, you have a choice between stage right, stage left, downstage right, downstage left. You might not be able to see everything … because you chose to watch something else. I like the idea that the audience can make choices and decisions. Generally it’s not like this — the audience is very passive.”

And though the show’s intimacy is clearly intended to stimulate the audience, its influence is not unilateral. “It brings a level of acting to your work,” Ms. Hamilton said. “For a lot of dancers, it’s just about the steps, and this is not. When it comes down to being onstage, it’s about the steps — yes — but it’s about everything that goes on top of it.”