非媒體-香蕉日報-Grażyna Brodzińska i B. Morka - Usta milczą, dusza śpiewa
in English it's usually known as the "Merry Widow Waltz," as it's from Franz Lehar's "Die Lustige Witwe" (English: "The Merry Widow.") Greetings from the U.S.