Washington DC (Map, News) - Benjamin Olinsky has a math degree from Yale and a day job in Sen. Edward Kennedy's office, but come this weekend, he'll direct D.C.'s 18th Street Singers, a 40-member community chorale. Their free concert will be Sunday at 12:15 p.m. at Bethesda's Music Center at Strathmore.

D.C. is full of class-president personalities. Are they a challenge to direct?

You know, I've never directed a group more committed and willing to pitch in. I think the Type-A personality tendencies get drained at work, so when they get to an activity afterward, they're happy to have it all set up for them.

How did the 18th Street Singers come to be?

It started in 2004. Myself and several friends had been involved in the music scene and had looked at options for choirs in town, but most weren't suited to our demographic or our time commitments at work, so we started our own.

What's your favorite piece to direct this Sunday?

Tough call. Probably "Water Night" by a young composer, Eric Whitacre. He combines the best of classical and modern styles and comes up with a shimmering sound. It's accessible, but new and interesting. And there's an incredible manner with which the music "text-paints."

Text-paints?

Yeah. The music is very reflective and almost heightens the meaning of the words - like if the lyrics talk about a current, or shimmering, or night, the music reflects that. And it's a very passionate piece. The lyrics are from a poem by Octavio Paz, the Nobel Prize-winning author.

What's the highest praise you've received?

We got an e-mail that said "I read somewhere the role of the arts is to remove the dust from our souls, and that's exactly how I felt during and after the concert." I got that and I thought, "That's why we're doing what we're doing."