By STEPHANIE CLIFFORD


Cellphones are hardly applauded in concert halls, where it’s considered gauche to have them turned on, much less to pull them out during a performance. So at a recent Indianapolis Symphony Orchestra concert, it was a little surprising when the conductor instructed audience members to take out their phones.

Symphony administrators had decided to let the audience choose the encore by text-messaging votes: “A” for Aaron Copland’s “Hoedown,” or “B” for Wagner’s prelude to Act III of “Lohengrin.” (“Hoedown” won by 23 votes.)

“There was a little hesitation on the part of the musicians at first, like, ‘What?’ ” said Samuel Banks, a 28-yearold bassoonist in the symphony. “It’s the cardinal sin to have your cellphone go off during concerts. It’s better to fall asleep than to have your cellphone go off.”

The symphony, faced with aging patrons, is trying to appeal to a younger audience. And, like other arts organizations, it is trying to make performances more interactive.

Along with the Indianapolis Symphony, the New York Philharmonic has also asked audience members to choose encores via text. In recent performances of Mozart’s “Cosi Fan Tutte” by a small opera company, attendees used text messaging to decide which couples would end up together. Museums, too, are using mobile technology in audio tours. It’s a shift for arts organizations, which typically select their own programs rather than ask for audience feedback.

The Indianapolis Symphony began offering text voting at performances last fall. “Vaudeville, cabaret, they’ve been taking requests for centuries now, and we’re a little late in getting on board,” Mr. Banks said. “We’re giving the patrons really their only opportunity to impact the programming, and it is very small, but it’s a nice gesture.”

Museums are also using cellphone technology: mobile phones are streamlined replacements for clunky audiotour handsets. The Walker Art Center in Minneapolis asks patrons to call a local number and enter a code, listed next to a work of art, for information about that piece. More than 500 museums, including the Brooklyn Museum, the Philadelphia Museum of Art and the National Portrait Gallery in Washington, D.C., use a service called Guide by Cell, which offers audio clips.

In at least one case, mobile technology has even been part of a director’s message. Gina Crusco, the artistic director of the Underworld Productions Opera Ensemble, asked audience members at a recent production in Manhattan to select which of the six main “Cosi Fan Tutte” characters should end up together.

“It’s up to the audience to fuse an ending that makes the most sense dramatically,” said Ms. Crusco.