The gorgeous and strange first movement of Beethoven's piano sonata Op. 27 No. 2 is one of the most popular piano pieces of all time, but there are many secrets that lie below its placid surface. We discuss some of the ways that the piece evokes moonlight and nocturnal landscapes. References The recording we used was played by Malcolm Bilson from "The Complete Piano Sonatas Played on Historical Instruments" Sarah Waltz, "In Defense of Moonlight" Tom Beghin, "Beethoven's Mondschein Sonata"