Listen to Piano Concerto No. 21 in C Major, K. 467: I. Allegro maestoso online. Piano Concerto No. 21 in C Major, K. 467: I. Allegro maestoso is an Instrumental language song and is sung by Emil Gilels, Rudolf Barshai and Moscow Chamber Orchestra. Piano Concerto No. 21 in C Major, K. 467: I. Allegro maestoso, from the album Mozart & Haydn: Piano Concertos, was released in the year 2013. The duration of the song is 13:42. Download Instrumental songs online from JioSaavn.