Piano Sonata No. 14 (Beethoven)
The name "Moonlight Sonata" started to become in use after the comments made by German music critic and poet Ludwig Rellstab about what the music reminded him of. In 1832, five years after Beethoven's death, Rellstab imagined the effect of the first movement like a moonlight shining above Lake Lucerne. Many agreed to this idea, and within ten years, the name "Moonlight Sonata" ("Mondscheinsonate" in German) was being used in German and English  publications. Later in the 19th century, it could be said that the sonata was "universally known" by that name.