Listen to Sonata No. 20 in G Major for Piano, Op. 49/2: I. Allegro ma non troppo online. Sonata No. 20 in G Major for Piano, Op. 49/2: I. Allegro ma non troppo is an English language song and is sung by Alfred Brendel. Sonata No. 20 in G Major for Piano, Op. 49/2: I. Allegro ma non troppo, from the album Alfred Brendel plays Beethoven: Selected Piano Works, was released in the year 2009. The duration of the song is 4:29. Download English songs online from JioSaavn.