Listen to String Quartet in B-Flat Major, Op. 18 No. 6: II. Allegro ma non troppo online. String Quartet in B-Flat Major, Op. 18 No. 6: II. Allegro ma non troppo is an English language song and is sung by Quatuor Mosaïques. String Quartet in B-Flat Major, Op. 18 No. 6: II. Allegro ma non troppo, from the album Beethoven: String Quartets Op. 18 Nos. 5 & 6, was released in the year 2016. The duration of the song is 7:34. Download English songs online from JioSaavn.