Listen to Mozart: String Quartet No. 17 in B-Flat Major, K. 458: II. Moderato (Excerpt) online. Mozart: String Quartet No. 17 in B-Flat Major, K. 458: II. Moderato (Excerpt) is an Unknown language song and is sung by Emerson String Quartet. Mozart: String Quartet No. 17 in B-Flat Major, K. 458: II. Moderato (Excerpt), from the album A Very Quick Guide to Mozart Vol. 2, was released in the year 2023. The duration of the song is 0:57. Download Unknown songs online from JioSaavn.