Music scholarship, whether historical or analytical, has tended to neglect sonata-form compositions after the deaths of Beethoven and Schubert in 1827 and 1828, respectively, particularly with regard to single-instrument compositions. A conventional, if perfunctory, definition – and one whose validity in the later nineteenth century this essay reappraises – typecasts sonata form as a musical structure in which two (or more) themes in contrasting keys are presented and developed, before being restated in the same key to bring closure to the movement. It is the formal design used in a majority of the first movements of solo sonatas, string quartets, symphonies and overtures in the eighteenth and nineteenth centuries. Scholarly neglect of this form is often justified in terms either of historical significance (the market for new piano sonatas, in particular, declined significantly in the middle decades of the nineteenth century) or of the perceived intrinsic flaws of individual sonatas produced after 1828 by composers such as Schumann, Chopin and Liszt, to name only the more familiar musicians.