NEW YORK - Ahh, the sounds of the subway. Trains rolling in and out of stations, service announcements over the speakers, the rushing footsteps of commuters.

And now, a washboard?

Yup, if Fred Gillen Jr. has his way.

Gillen and his friend Matt Turk were among dozens of musicians and performers who made their way to Grand Central Terminal's Vanderbilt Hall on Tuesday to audition for the Metropolitan Transportation Authority's Music Under New York program.

While plenty of people toot horns or sing their way through the system, there are only about 100 or so acts that are officially recognized by the MTA, getting prime performing spaces in some of the busiest stations. Every year, about 20 spaces open up on the roster, so auditions are held to fill them.

Tuesday's auditions, with about 70 performers taken from 200 submissions, covered a musical range, from folk rock to electric violin.

Gillen used a brush and a marker to play his washboard as Turk strummed the guitar.

The friends, both music professionals, looked to the subway to provide a new experience.

“You get an opportunity to be spontaneous and catch people who are not looking for you but yet all of a sudden are right there in front of you,” Turk said.

Sixteen-year-old Banks Harris, of Brooklyn, skipped school along with companion Kane Dulaney Balser, also 16, for the chance to audition in front of more than two dozen judges, impressing many with her deep, powerful singing voice.

The two were looking for the official sanction for subway playing.

“We've done it before, but we'd feel better if we had a permit,” Balser said, adding that otherwise there was more of a chance they could be rousted or asked to stop by police or, hey, annoyed subway riders.

While they've made some money doing it, Harris said the main draw was the chance to perform.

“It's the greatest audience,” she said.

The program, which started as a pilot in 1985, is part of the MTA's Arts for Transit, which also places visual art in the subway system. Music Under New York organizes more than 150 performances a week at 25 locations, including Grand Central Terminal, Pennsylvania Station and the subway stations at Times Square and Union Square.

The roster includes everything from a barbershop quartet to a mime.

“In many ways it really is a gift to the city and to other New Yorkers,” said Sandra Bloodworth, director of Arts for Transit.

The artists on the roster are given the chance every two weeks to call in and make requests for time slots.

Every performer is given a banner from the MTA to signal participation in the program. The artists, as street performers, are allowed to take whatever money they're given from passers-by.

Participating in the program has been a boon for some, Bloodworth said, because of the exposure it provides.

She pointed to the example of Susan Cagle, the singer-songwriter who signed a record contract and has appeared on Oprah Winfrey's television show.

“There's a specialness to it,” Bloodworth said. “It has been for many years quite an honor to be part of the program.”

Not everyone can do it, though. Artists have to have more than just talent, they have to have a performance that can translate in the crowded, noisy subway system.

The artists who do make it add a certain something to the experience of subway travel, even if their audience only hears them for a passing moment, said Jenneth Webster, producer of Lincoln Center's Out of Doors Festival and an audition judge.

“My feeling,” she said, “is that the perception of art even for the moment should change your life.”