Beethoven piano sonata opus 27 2 1 loop - Classical Loop - 0:51 - The Piano Sonata No.14 - 1st movement (Adagio sostenuto) in C sharp minor "Quasi una fantasia" (Almost a fantasy), op. 27, No. 2, by Ludwig van Beethoven, popularly known as the Moonlight Sonata was completed in 1801. The name "Moonlight" Sonata derives from an 1832 description of the first movement by music critic Ludwig Rellstab, who compared it to moonlight shining upon Lake Lucerne.