In 1809, E. T. A. Hoffmann declared that the symphony, in the hands of Haydn and Mozart, had become the “opera of instruments.” This view of symphony, which was echoed by other writers of the period, reflected how composers engaged with instruments through orchestration. This essay explores the use of instrumental sonority in the slow movements of Haydn’s later symphonies, in particular looking at the ways in which Haydn’s approach to the orchestra helped cultivate the notion that symphonies unfolded as dramas. This conception of the orchestra and of orchestration informed the language of musical criticism of the early nineteenth century: Hoffmann’s discussions of musical works frequently take the form of operatic plot summaries, in which individual instruments act as characters. The persistence of operatic metaphors suggests that, instead of thinking of this period as the “rise of instrumental music,” it is more accurate to understand it as the rise of the orchestra.