Du und Du (Thou and Thou, or alternatively, You and You), opus 367, is a waltz composed by Johann Strauss II in 1874. The waltz features themes from Strauss' operetta Die Fledermaus. The title of the piece, as well as one of its melodies, was taken from the famous Dui-du chorus in "Bruderlein, Bruderlein und Schwesterlein" (Act Two).
References
Du und du Wikipedia(Text) CC BY-SA