Frederic Chopin
Nocturne No. 20 in C-sharp minor, Opus posthumous
Lento con gran espressione
This Chopin Nocturne is one of his most famous nocturnes though it was published after his death (posthumously). It was featured in the great Roman Polanski film “The Pianist” and other movies. It has a very interesting story and more about it one can read at the related article in Wikipedia.