Listen to Piano Concerto No. 15 in B-Flat Major, K. 450: III. Allegro online. Piano Concerto No. 15 in B-Flat Major, K. 450: III. Allegro is an English language song and is sung by Studying Music Group. Piano Concerto No. 15 in B-Flat Major, K. 450: III. Allegro, from the album Classical Music for Study 2017 – The Best Chill Out Compilation, Music for Learning, Study, was released in the year 2017. The duration of the song is 3:32. Download English songs online from JioSaavn.