Klaviersonate Nr. 14 op. 27 Nr. 2 (Moonlight Sonata) by Ludvig van Beethoven

It was written in 1801 and originally named Quasi una fantasia.
The piano sonata was dedicated to his pupil Giulietta Guicciardi.
​
The third movement is believed to be inspiration of Frederic Chopin's Fantaisie-Impromptu, which is a tribute to Beethoven.