Before the New York Philharmonic presented its first concert of the season in Central Park last week, the executive director of the orchestra had an announcement: Audience members could vote for an encore from the evening’s soloist by text message. The choices were a Chopin étude or, in honor of the guest musicians from the Shanghai Symphony Orchestra, a traditional Chinese melody.

The Chinese melody won, and so did marketers for the soloist, the piano virtuoso Lang Lang. Voters swiftly received a reply offering a discount to “pre-order” his new CD set, “Live in Vienna,” and an invitation to follow him on Facebook.