4 in D major, K. 203/189b was written in August 1774 by Wolfgang Amadeus Mozart for ceremonies at the University of Salzburg.
The work is very similar to the serenade K. 204 composed for Salzburg the following summer.
The serenade is scored for two oboes (doubling flutes), bassoon, two horns, two trumpets and strings.
There are eight movements: The March in D, K. 237/189c, was used as an introduction or exit for this work.
[1] The trio of the second minuet features an independent solo bassoon part.