Listen to String Quartet No. 15 in D Minor, K. 421: I. Allegro moderato online. String Quartet No. 15 in D Minor, K. 421: I. Allegro moderato is an Unknown language song and is sung by Barchet Quartet. String Quartet No. 15 in D Minor, K. 421: I. Allegro moderato, from the album Mozart: Complete String Quartets, Vol. 4, was released in the year 1960. The duration of the song is 8:34. Download Unknown songs online from JioSaavn.