<Ul> <Li> WoO 63: Nine variations for piano on a march by Ernst Christoph Dressler (1782) </Li> <Li> WoO 64: Six Variations on a Swiss song for piano or harp (1790--1792) </Li> <Li> WoO 65: Twenty - four variations for piano on Vincenzo Righini's aria "Venni Amore" (1790--1791) </Li> <Li> WoO 66: Thirteen variations for piano on the aria "Es war einmal ein alter Mann" from Carl Ditters von Dittersdorf's opera Das rote Käppchen </Li> <Li> WoO 67: Eight variations for piano four hands on a theme by Count Waldstein </Li> <Li> WoO 68: Twelve variations for piano on the "Menuet a la Vigano" from Jakob Haibel's ballet La nozza disturbate (1795) </Li> <Li> WoO 69: Nine variations for piano on "Quant'e piu bello" from Giovanni Paisiello's opera La Molinara </Li> <Li> WoO 70: Six variations for piano on "Nel cor più non mi sento" from Giovanni Paisiello's opera La Molinara (1795) </Li> <Li> WoO 71: Twelve variations for piano on the Russian dance from Paul Wranitzky's ballet Das Waldmädchen </Li> <Li> WoO 72: Eight variations for piano on "Une Fièvre Brûlante" from André Ernest Modeste Grétry's opera Richard Coeur - de-lion </Li> <Li> WoO 73: Ten variations for piano on "La stessa, la stessissima" from Antonio Salieri's opera Falstaff </Li> <Li> WoO 74: "Ich denke dein"--song with six variations for piano four hands </Li> <Li> WoO 75: Seven variations for piano on "Kind, willst du ruhig schlafen" from Peter Winter's opera Das unterbrochene Opferfest </Li> <Li> WoO 76: Eight variations for piano on "Tändeln und scherzen" from Franz Xaver Süssmayr's opera Soliman II </Li> <Li> WoO 77: Six easy variations on an original theme for piano </Li> <Li> WoO 78: Seven variations for piano on "God Save the King" </Li> <Li> WoO 79: Five variations for piano on "Rule Britannia!" </Li> <Li> WoO 80: Thirty - two variations on an original theme in C minor for piano </Li> </Ul> <Li> WoO 63: Nine variations for piano on a march by Ernst Christoph Dressler (1782) </Li> <Li> WoO 64: Six Variations on a Swiss song for piano or harp (1790--1792) </Li> <Li> WoO 65: Twenty - four variations for piano on Vincenzo Righini's aria "Venni Amore" (1790--1791) </Li>

When did beethoven compose his six easy variations on a swiss tune in f major for piano