Eine kleine Nachtmusik (Serenade No. 13 for strings in G major), K. 525, is a 1787 composition for a chamber ensemble by Wolfgang Amadeus Mozart (1756-1791).
The German title means "a little night music" and is one of Mozart's most famous works.
The serenade is written for an ensemble of two violins, viola, cello, and double bass, but it is often performed by string orchestras.