Mozart's 'Eine kleine Nachtmusik' is a serenade composed in 1787 by Wolfgang Amadeus Mozart. It is one of the most popular pieces of classical music and is often referred to as a 'little night music'. The piece consists of four movements and is written for a chamber ensemble of two violins, viola, and cello. It is a perfect example of the Classical period style of composition, with its graceful melodies and balanced structure.