For 10 points, name this piano piece by Ludwig van Beethoven.
The cadenza from this composition's third movement is quoted in the fourth measure of melody in Chopin's Fantasie Impromptu. This work's adagio sostenuto first movement contains the instruction for the sustain pedal to be held down continuously in its duration, and it was dedicated to the composer's pupil, Countess Julie Guicciardi. This C-sharp minor piece is its composer's fourteenth in a genre he heavily innovated. Originally called "Quasi una fantasia," it was nicknamed by Ludwig Rellstab due to its evocation of Lake Lucerne at night. For 10 points, name this piano piece by Ludwig van Beethoven.
The cadenza from this composition's third movement is quoted in the fourth measure of melody in Chopin's Fantasie Impromptu.
{“Moonlight” Sonata} [accept {Piano Sonata} No. {14} in C-Sharp Minor]  