Claire Daly works with students participating in the Capitol Jazz Camp. (Courtesy Washington Performing Arts Society)

Midway through the National Symphony Orchestra’s concert last weekend, a conductor took the stage.

A train conductor.

Kevin Kelly, a uniformed Amtrak employee, stepped onto the podium in Union Station, curled one hand authoritatively behind his back, grasped the baton in the other and energetically led several measures of Offenbach’s “Can-Can.” The floor rumbled with the vibrations of trains and Metro railcars.

By leaving the Kennedy Center’s walled-in arts preserve to offer a railroad-themed program in the station’s cavernous East Hall, the NSO is part of a national trend. It’s increasingly harder to get people into a concert hall. Even people who love Beethoven and Brahms and Stravinsky are happy to listen to their music at home on a computer or smartphone rather than buying a pricey ticket. So performing arts organizations from Baltimore to Chicago to Detroit are trying to reach new audiences — by coming to them.

Hence a program such as “NSO in Your Neighborhood,” which brought the orchestra to the Capitol Hill and H Street NE area for 50 free performances in schools, community centers, homeless shelters, coffee shops — and the train station.

The same impetus is behind the Washington Performing Arts Society’s new plan to engage an “urban arts curator” to scout out non-professional musicians and ensembles who might be interested in collaborating with some of the artists WPAS brings to town. The “Mars Urban Arts Initiative,” funded by a $1.42 million, multiyear grant from the Washington region arts patron Jacquie Badger Mars and the candy company Mars, is scheduled to start in the next few months.

“I envision joint music-making,” says Jenny Bilfield, WPAS’s president and chief executive, with the “participation of people who are active arts makers but haven’t chosen to make it their life’s work.”

“We valorize artists who perform at the highest level for a reason, but arts are accessible at many different levels,” she says.

The NSO’s program — which in its previous two years has taken the orchestra to Columbia Heights and the U Street-Shaw area — seems to be demonstrating that geography and price are significant factors in, or deterrents to, attendance.

According to Rita Shapiro, the orchestra’s executive director, audience surveys showed that the two main reasons people attended the concerts, which ranged from a quartet of violinists gamely playing for an audience of restless toddlers in the basement of Ebenezers Coffeehouse on F Street NE to full orchestral performances at the Atlas Performing Arts Center, were “because it was free” and “because you came to my neighborhood.”

At the Atlas concert Wednesday night, according to the Atlas’s director of marketing, Renee Littleton, a significant part of the audience lived within walking distance.

“I don’t take that lightly,” Shapiro says. “I think it’s really important for the NSO to get out of the Kennedy Center and connect with different neighborhoods.” Plus, she said: “I’ve always wanted the orchestra to play at Union Station. . . . It’s just a cool thing to do.”

In its forays into the city, the NSO is effectively jumping on a national bandwagon. The Philadelphia Orchestra, the Cleveland Orchestra and the Detroit Symphony Orchestra are just a few of the orchestras that present neighborhood concerts, ranging from free one-off performances to week-long residencies.

The NSO’s history of outreach over the years illustrates the ways that the philosophy of outreach has gradually shifted. For almost 20 years, the orchestra’s American Residencies program traveled to states where people didn’t have much access to live classical music, performing in schools and community centers in South Dakota and Alaska, as well as in venues in West Virginia and 18 other states. The assumption — prevalent among classical-music lovers — was that the orchestra was bringing the treasure of its music to the masses: It was an essentially didactic approach.

Today, outreach is about finding ways to connect as equals with the population around you: an exchange, not a lesson. It’s true that a lot of people in the District may not attend many live classical music performances. But last week’s concerts seemed to draw a healthy number of middle-income attendees.

And when Ankush Kumar Bahl, the NSO’s assistant conductor, introduced a piece that it played at the Atlas as “by a composer named Ludwig van Beethoven,” there was an audible titter in the house. It’s a pretty safe assumption that anyone willing to sit through an orchestra concert, even a free one, knows who Beetho­ven is. We have met the outreach audience, and they are us.

Indeed, the whole point of the WPAS initiative is that finding and working with amateur musical communities are ways to establish a dialogue that’s vital to the organization’s mission. “I felt it needed to be central within WPAS,” Bilfield says. “I didn’t want to do it on a project basis or consulting basis, appended to it like a barnacle.”

Bilfield, who started in April and who has run what was formerly Stanford’s Lively Arts program and the American arm of the music publisher Boosey & Hawkes, is working on expanding WPAS’s programming mandate to include more kinds of performers. The urban arts initiative is a reflection, or even an extension, of that goal.

“Introducing our audiences to community-based work in addition to professional touring work” is how Bilfield summarizes it. “I think if people understand the roots of these activities better, they can see their own role in maintaining cultural practice.”

The model Bilfield is suggesting — bringing in a curator to unearth the variety of things that are going on in Washington under the audience’s radar — is new. The idea of using the arts for social interaction is not.

The Chicago Symphony Orchestra’s Citizen Musician Initiative is, in the words of the cellist Yo-Yo Ma, “open to and inviting of people of all colors and stripes, not just professional musicians but members of the civic orchestras and administrators,” to engineer social change.

In Baltimore, the orchestra programmed a whole season a few years back with an eye to the different ethnic communities in that region, including Hungarian emigres and transplanted Southerners.

Individual artists are doing their own forms of outreach: The composer Tod Machover solicited contributions from the entire population of Toronto for “A Toronto Symphony,” while the composer-pianist Vijay Iyer worked with veterans of color of the Iraq and Afghanistan wars for “Holding It Down: the Veterans’ Dream Project.”

“Everybody is looking at what it means to be part of the community,” says Margaret M. Lioi, the chief executive of the service organization Chamber Music America.

Chamber music ensembles, more flexible and portable than a 100-piece orchestra, have led the way in reaching out beyond the walls of the concert hall. “These are not any longer what used to be called outreach activities,” Lioi says. “These are actual performances taking place in community locations such as bookstores or yoga studios or coffee shops. . . . It’s very much a part now of the fabric of the chamber music field.” Ensembles are no longer simply performing to an audience “sitting in the dark, behaving.”

Even with the large-scale orchestral residencies, some of the impetus may be that the musicians find the work fulfilling. No one supposes that a few concerts in Union Station are going to lead to a bunch of new subscribers in the Kennedy Center Concert Hall. But they might be able to expand awareness of the orchestra in the District — and expand the orchestra’s awareness of itself.

“I don’t think [such residencies are] primarily a marketing and audience-development strategy in the near term,” says Jesse Rosen, the president and chief executive of the League of American Orchestras. “I think it’s more around creating public value, creating greater accessibility and creating more varied ways for musicians to express themselves.”