The Mendelssohn of the Eighteenth Century: Tonal Growth, Functional Fluidity and Formal Complication in the First Movement of the D Major Quartet, Op. 44 No. 1

ABSTRACT This article examines the elaborate compositional processes at work in the opening movement of Mendelssohn's Quartet in D major, Op. 44 No. 1 (1838) in the service of advancing and further refining the application of contemporary Formenlehre to nineteenth‐century music. Most conspicuous of these features is the role taken by the key of F♯ minor, iii of the tonic, which assumes increasing prominence over the course of the exposition, culminating in a curious ostensible secondary theme (bar 71) which appears initially to contradict the tonality of A major just confirmed. This harmonic argument runs alongside a fluid approach to phrase and interthematic structure, in which not only are the erstwhile first theme and transitional material subject to functional transformation but the latter is further elided with potential secondary material, while no terminating cadence (or EEC) is present either. Current analytical approaches – foremost here, sonata theory – cannot fully elucidate the subtlety of Mendelssohn's procedure (one might variously argue for an overridden medial caesura, a secondary theme starting in multiple places, a continuous or even a failed exposition), and nonetheless, clear precedents for individual elements of Mendelssohn's design can be found earlier in the music of Haydn and Mozart. Mendelssohn's movement raises significant questions about recent approaches to theorising nineteenth‐century form and its relation to Classical precedents, not all of which can be easily answered.