Listen to Piano Sonata No.16 in C major, K.545 "Sonata facile": 1. Allegro online. Piano Sonata No.16 in C major, K.545 "Sonata facile": 1. Allegro is an English language song and is sung by Walter Klien. Piano Sonata No.16 in C major, K.545 "Sonata facile": 1. Allegro, from the album The Most Essential Classical Music for Your Baby, was released in the year 2008. The duration of the song is 2:54. Download English songs online from JioSaavn.