Lydia Goehr (2015) contends that at the beginning of the nineteenth century, the work concept profoundly changed the nature of the prelude: "the practice of preparatory preluding became the art of a Romantic prelude already prepared" (para. 8, emphasis mine). By its very nature, the prelude is incomplete, as a primarily functional genre that gains the audience's attention and offers performers the chance to ready themselves for the main performance. And yet this genre gained musico-aesthetic respectability in the Romantic era, and the "preparatory" function become thornier. In this paper, I trace this function in another preparatory formal unit: the eighteenth-century introduction. Although Beethoven's novel introductory procedures had a pronounced influence on early Romantic composers, I analyze two unusual introductions in the Classical period in order to offer a fuller context for the phenomenon of aestheticized beginnings: the multi-stage beginning found in the finale of Mozart's Serenade in D, K. 250 (1776) and the recurring introduction in the opening movement of Haydn's "Drumroll" Symphony No. 103 (1795). Employing the theoretical framework and analytical perspectives in Hepokoski and Darcy's Sonata Theory (2006), I contend that these classical movements confound the binary of "inside" versus "outside" the sonata in unusual ways. Simultaneously, however, I also argue that these compositional experiments are different in kind from later ones, insofar as the shifts in the level of discourse (Hatten 1991) are not so rhetorically emphatic or structurally disruptive as in nineteenth-century examples (e.g., Beethoven's "Galitzin" quartets and Mendelssohn's overtures, Op. 21 and 32).