Brian Sacawa and Erik Spangler see themselves as sound guerrillas.

The co-founders of the Contemporary Museum's off-kilter Mobtown Modern concert series don't just perform experimental music - sometimes they like to sneak up on people with it.

That's the case with Mobtown Modern's latest project, a rendition of Mauricio Kagel's Eine Brise (A Breeze), subtitled "Fleeting Action for 111 Cyclists."

No, that number's not a typo. The piece features a troupe of 111 bicyclists, who whistle, ring bells and make whooshing noises with their breath while riding to re-create the sound of a breeze. Sacawa and Spangler are organizing a performance of Eine Brise on Saturday in the Station North Arts and Entertainment District, which will coincide with Artscape.

The stretch of Charles Street from Mount Royal Avenue to Lafayette Avenue will be closed for Artscape, the country's largest free arts festival. That will give the cyclists some elbow room on an otherwise crowded street. The festival also features exhibitions by hundreds of artists, performances by an eclectic array of musicians, including Cake, Dionne Warwick and Robert Randolph and the Family Band, as well as countless craft and food vendors.

But the duo aren't disclosing many specifics of the event - namely, where the cyclists will be riding - because they want it to have some shock value for unsuspecting Artscape patrons. The only certainty is that participants will gather outside the Metro Gallery at 3 p.m. From there, it's anybody's guess.

"People who don't live in the city might not be expecting it," Sacawa said. "We want it to be a bit of a surprise and have a little bit of a 'What the hell is that?' quality to it."

Outsiders to the world of experimental contemporary art and music might ask the same question of many Mobtown Modern concerts. The series began in January 2008 at the Contemporary Museum with performances centered on former President George W. Bush's final State of the Union address. Since then, Mobtown Modern has won praise from music critics, and recently moved to a new location, at the Metro Gallery in Station North.

"Contemporary music tends to be a little scary to some people," Sacawa said. "We want to make it as interactive as possible. A lot of our shows make it so people can be part of our performances."

Several months ago, one of Sacawa's friends suggested he stage the 111-cycle extravaganza, since it brings together two of Sacawa's passions: cycling and music.

"I like cycling for some of the same reasons that I decided to pursue music and got four degrees in music performance - it's something you can do for your entire life," he said. "There's never a time in music or cycling when you can say, 'I'm the best in the world. There's always room for self-improvement."

So far, a number of people have signed up to perform Eine Brise, Spangler said. But have they hit 111?

"I'm hoping we get to that number," Spangler said. "I'm not sure if we've gotten there yet or not."

Even if Spangler and Sacawa fall short of the 111 cyclists, the show will go on, they said. And if they get too many people, they won't turn anyone away. Any extra participants can tag along with the rest of the pack.

Music professor and saxophonist Michael Ibrahim will be making the three-hour drive from West Virginia to Baltimore to participate in Saturday's performance. That's a six-hour round-trip for a five-minute show. Even if Sacawa and Spangler decide to repeat the performance a couple times - which is pretty likely, they said - that still amounts to less than 30 minutes of cycling, whistling and whatnot. But Ibrahim is undeterred.

"It seemed like an obvious thing to do for the summer," Ibrahim said. "I'm happy to say this will be my first Kagel work on a bike."

In terms of eccentricity, Eine Brise is par for the course for Kagel. The German-Argentine composer, who passed away last year, penned many such scores, with the idea of bringing together music and theater in an unconventional, almost absurdist, performance. He composed Con Voce, (With Voice), a piece in which three masked musicians mimic playing their instruments, and Match, a tennis game performed by cellist with a percussionist playing the role of the umpire.

"All of his works are really interesting," Ibrahim said. "He's really important within the 20th century. I think he's quite underrated and overlooked."

Even with some knowledge of Kagel's works, Ibrahim is not entirely sure how Saturday's event is going to come off.