Listen to Instruments of the Orchestra: Mozart: Duo for Violin and Viola in B-Flat Major, K. 424: finale: variations 1 and 2 online. Instruments of the Orchestra: Mozart: Duo for Violin and Viola in B-Flat Major, K. 424: finale: variations 1 and 2 is an English language song and is sung by Jeremy Siepmann. Instruments of the Orchestra: Mozart: Duo for Violin and Viola in B-Flat Major, K. 424: finale: variations 1 and 2, from the album Instruments of the Orchestra (The), was released in the year 2002. The duration of the song is 2:18. Download English songs online from JioSaavn.