Listen to Piano Concerto No. 1 in B-Flat Minor, Op. 23: I. Allegro non troppo e molto maestoso online. Piano Concerto No. 1 in B-Flat Minor, Op. 23: I. Allegro non troppo e molto maestoso is an English language song and is sung by Milena Molova. Piano Concerto No. 1 in B-Flat Minor, Op. 23: I. Allegro non troppo e molto maestoso, from the album The Greatest Classical Music Collection, was released in the year 2014. The duration of the song is 4:32. Download English songs online from JioSaavn.