The Andante cantabile of the “Jupiter” is a kind of distillation of its companions in the symphonies of 1788 and in the “Prague,” since it is considerably shorter yet no less powerful. Indeed, whereas the outer movements of these works are remarkably distinct from each other in musical personality, the slow movements all disrupt their lyrical flow with disturbing transitional passages of powerful emotional expressiveness. We simply do not see this in earlier symphony Andantes by Mozart. But we have seen it in some of the piano concertos of Mozart's glory years in Vienna, 1784–6, and the suggestion may be advanced that those concertos deepened his later symphonic slow movements just as they transformed his orchestration. I will refer to the works by their numbers here so as not to create confusion in keys (for example, the slow movement of the G minor is in ♭, major, the key of a different symphony).

“Expressive episodes”

In Mozart's last four symphonies, the Andantes initially induce a reverie in the beautiful sound-world of their principal themes, only to shatter it with varying degrees of force in a suddenly forte transitional passage. All but No. 40 turn to minor at that point, and all within a few bars move toward (or farther around) the flat side of the circle of fifths, which gives emphasis and poignancy to the stirring rhythms, syncopations, offbeat accents, and other signals of heightened affect.