Description: Beethoven's Sonata No. 14 in C-sharp Minor Moonlight Sonata or Sonata quasi una fantasia, Op.27, No.2, is among the best loved and most frequently performed works of any composer. The nickname "moonlight" probably came from a poetic phrase used to describe the sonata in about 1832, four years after Beethoven's death. Many editions of this popular sonata are available in either the complete sonata or just the most popular first movement.