Frédéric Chopin composed the Introduction and Variations on the German Air "Der Schweizerbub" (often referred to as 'Variations sur un air national allemand') in 1826/27. It is a single movement piece, and, since it doesn't have an Opus number, it usually listed as B. 14 according to the Brown Catalogue of Chopin's works. It was first published in 1851. A standard rendition lasts 7 minutes.