Sonata No. 2) Beethoven, Ludwig van. Piano solo. Piano Sonata No.20 in G major, Opus 49.2. 49, No. Charles Rosen, while noting the sonata's lack of technical challenges, states that it is a "deeply affecting and distinguished work". 20 was probably written around the time Beethoven composed the 3rd and 4th sonatas, but because it was published in Vienna in 1805, nearly a decade after it was written, it was assigned then-current opus and sonata numbers, placing it amid works from the composer's middle period. 20 (1st Movement: Allegro ma non troppo) (Op. Piano solo. 11 sheets found. Ludwig van Beethoven Piano The Piano Sonata no.