Which song traditionally begins the New Year in Vienna's New Year's Concert broadcast?

The Blue Danube traditionally begins the New Year in the Vienna New Year's Concert broadcast.

Johann Strauss II composed “The Blue Danube,” formally titled “An der schönen blauen Donau,” in 1866. It became one of the most recognizable works associated with Vienna and is a signature part of the annual concert tradition. In the concert's customary sequence, the piece is performed as the first encore after the main program rather than as the first scheduled work.

The Vienna New Year's Concert is performed by the Vienna Philharmonic at the Musikverein. The Radetzky March is another famous encore and is usually the final work, accompanied by audience clapping. This ordering explains why descriptions sometimes call The Blue Danube the concert's “opening” piece in a ceremonial sense.