The Blue Danube
The Blue Danube was a waltz composed by Johann Strauss II of Earth in the 19th century.

In order to celebrate Captain Benjamin Sisko's approval of taking their analysis regarding the Dominion War to Starfleet Command in 2374, four genetically-engineered Humans, , Lauren, Patrick, and Sarina Douglas held a party with Doctor Bashir. They drank champagne and danced to Strauss' Blue Danube waltz. ()

In 2378, The Doctor played the Blue Danube waltz in one of his recitals. When he and Captain Janeway were abducted by Overlooker renegades, The Doctor altered a recording of the waltz so that it would sound out of tune. By performing a Fourier analysis, Seven of Nine found out that the harmonics of the piece had been modified to imitate a warp signature. The crew was able to track the signature and thereby locate The Doctor and the captain. ()

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de:An der schönen blauen Donau
fr:Le beau Danube bleu
Blue Danube, The