The Blue Man Group is looking for new talent.

Thursday is the last day of a three-day audition at the Briar Street Theatre. Performers will compete for the chance to paint themselves blue and perform comedy and music on stage.

They will go through an interview, act in front of the casting department from New York, then play drums with music director and veteran blue man drummer Jeff Quay.

Around 50 men lined up outside the theatre Tuesday hoping to join the team.

Collin Batten, who has been a blue man in Chicago for the past four years, says it’s hard to describe what the crew is looking for, apart from the an athletic, 5-foot-10 to 6-foot-1 build, drumming and acting skills.

“It’s something that we just ended up calling the ‘X factor,’ that unknown spark in somebody’s eyes that comes out and separates them out from the crowd,” he said.

Production Stage Manager Nykol Dedreu says it’s all about the eyes. The performers don’t speak in the show and need to communicate with their eyes and body language.

She also notes that aspiring performers need not be bald men. The group welcomes women, though they are rare because of the specific body shape required.

“They all have to be kind of matching on stage, so you don’t really as an audience member tell one from the other — it’s the personality, not the look,” she says. “So to have a girl blend with that, that’s kind of a rare shape and form for a female.”

The group did cast one female as a performer, and another woman made it to the last round of the open auditions in April 2011.

Aaron Legg flew in from Florida to audition. As applicants sat nervously next to the box office, he got out drumsticks and practiced on the floor.

He’s only seen the group perform once, but their unconventional instruments and music attracted him. The self-taught drummer hasn’t stopped playing since the age of 11 and he now performs at Sea World.

“I used to cut pool sticks in half just to be able to play,” Legg said. “We build our drums out of tool boxes and traffic cones and they build their stuff out of PVC pipes so I can sort of feel a connection.”

Finalists will go to an acting workshop, and play a scene in the full blue and bald getup before the casting crew make their decision.

The theatre group doesn’t yet know how many people they’ll take. Dedreu says they’ll stop hiring when they have too many Blue Men.

Alan Yu is a WBEZ reporting intern. Follow him @Alan_Yu039.