Mozart Completes Symphony No. 40
Wolfgang Amadeus Mozart wrote his Symphony No. 40 in G minor, KV. 550, in 1788.
It is sometimes referred to as the "Great G minor symphony," to distinguish it from the "Little G minor symphony," No. 25. The two are the only minor key symphonies Mozart wrote.
The composition occupied an exceptionally productive period of just a few weeks in 1788, during which time he also completed the 39th and 41st symphonies (26 June and 10 August, respectively).
There is no completely solid documentary evidence that the premiere of the 40th Symphony took place in Mozart's lifetime. However, as Zaslaw (1983) points out, the circumstantial evidence that it was performed is very strong.