True woodwind music makes up a distinct unit among Mozart's chamber output, although these works are not chamber music in the literal sense as they were intended for outdoor performance. In the early 1780's, Mozart composed a number of significant woodwind pieces. The most important for the composer was undoubtedly the C minor wind serenade which was written in the summer of 1782 in Vienna. Mozart's affection for it is shown by his decision to transcribe it for string quintet a few years later (K. 106/516/b). This is Mozart's first truly significant C minor composition. It has great momentum and is full of constant tension. Its tonality is unusual – its heroic, passionate, and often funereal associations make it more the stuff of chamber music than street serenade music.
The principal theme of the opening Allegro itself conceals a minor drama, but the Andante eloquently expresses both suffering and agony. With its pulsating inner voices, decisive, sharp and jutting stresses, the internal formal organisation goes far beyond the boundaries of incidental street music with its unusual individuality. The Menuet is no less remarkable. Mozarts writes “In Canone” above it, which indicates its contrapuntal textures, another feature far removed from the traditional demands of evening serenade music. The movement boasts a crab cannon (one of the more refined tricks of the trade of a contrapuntalist), which while technically owing much to the baroque, in this instance evokes the world of Haydn. The Allegro finale is a set of variations, the instrumental ideas of which are much more multi-layered than we would expect for this genre. Knowing that Mozart – as he wrote in a letter – composed this work with remarkable haste, we can appreciate that even when scribbling down what is essentially a piece of incidental music, he was unable supress his demanding musical inventiveness.