Concertante in G for 2 oboes, 2 flutes, 2 bassoone and orchestra after the Serenade in D KV 320

The symphony was the most important genre of instrumental orchestral music during the Classical era. Different local traditions in symphonic composition developed, and Mozart easily adapted to these local influences at different times during his travels. During the Grand Tour of Western Europe of 1763–1766, he wrote 15 symphonies, many of which are now lost, and these variously followed the fashions then current in England and the Netherlands. Further works were composed during the stays in Vienna and Italy in 1767–1768 and 1769–1771. These symphonies require a standardized orchestra of 2 oboes, 2 horns, and strings. Festive symphonies additionally employed 2 trumpets and timpani.

The majority of Mozart’s symphonies were written during his Salzburg years. With few exceptions, they were destined for the concerts held at the court of the Prince-Archbishop and did not circulate during Mozart’s lifetime. A peculiarity at the Salzburg court was that the same musicians used to play both transverse flutes and oboes. Thus, while the instrumentation sometimes varies from one movement to the other, oboes and flutes were generally not used at the same time in these symphonies. A considerable number of works were derived from opera overtures, for which Mozart wrote a finale if they did not end with a fast movement. Still others were adaptations of orchestral serenades, with Mozart reducing the number of movements to three or four.

During his Vienna years, Mozart composed a small number of symphonies, which have become some of his most popular works. This is particularly true for a series of three symphonies composed in the summer of 1788, among them the so-called “Jupiter” Symphony, KV 551. The Vienna symphonies are not only characterized by their greater scope, but also by more extensive and varied instrumentation. An additional flute was often added; and occasionally 2 clarinets replaced or supplemented the oboes, while the bassoon parts became more and more independent from the orchestral bass line.