Listen to Beethoven: 12 Variations for Cello and Piano on "See the Conquering Hero Comes", WoO 45: Theme. Allegretto online. Beethoven: 12 Variations for Cello and Piano on "See the Conquering Hero Comes", WoO 45: Theme. Allegretto is an Unknown language song and is sung by Mischa Maisky and Martha Argerich. Beethoven: 12 Variations for Cello and Piano on "See the Conquering Hero Comes", WoO 45: Theme. Allegretto, from the album Reading Goethe, was released in the year 2020. The duration of the song is 0:42. Download Unknown songs online from JioSaavn.