Radetzky March
At the end of a concert, if there is prolonged applause, one more relatively short piece may be performed as an encore. In some modern circumstances, encores have come to be expected, and artists often plan their encores. Traditionally, in a concert that has a printed set list for the audience, encores are not listed, even when they are planned. A well-known example is the performance of the "Radetzky March" and "The Blue Danube" at the end of the Vienna New Year's Concert by the Vienna Philharmonic Orchestra; neither piece is ever listed in the official program, but they are traditionally played every year.