Some Multimovement Designs in C. P. E. Bach's Late Keyboard Sonatas

This paper takes as its point of departure Johann Nikolaus Forkel's 1784 review of C.P.E. Bach's Sonata in F minor (W57/6), which contains an early discussion of multimovement organization in instrumental music. The essay is noteworthy because, among other things, Forkel treats movements as wholes; in addition, he attempts to describe a progression through the three-movement cycle. This paper identifies three of the techniques that help organize multimovement designs in the sonatas für Kenner und Liebhaber.

(1) Ruptures in the first-movement fabric. In the C-major Sonata W55/1 Bach prepares but evades the conventional cadence at the end of the second main period (development section), here a cadence in E minor. A signature motif B-A-C-H takes over the bass, leaving E minor to the slow movement. The finale recalls what happened, giving the signature motif a new character appropriate to the finale.
(2) Related head motives in all three movements. In the D-minor Sonata W57/4 Bach opens the first two movements with motifs of very different character that are nonetheless related as melodic turns around D. The finale plays out the contrasting notes in these two turns (E and E-flat), integrating that contrast, sometimes shockingly, into most of its phrases.
(3) Run-on movements. In the G-major Sonata W56/2 a peculiar tonal contrast in the first-movement development section influences the run-on Larghetto, so that the entry of the Allegro finale revisits the motion into the first-movement recapitulation. In this way the three-movement "cycle" shares features with the three-period opening movement, anticipating, at least in that limited way, the "two-dimensional" sonatas described by Vande Moortele (2009).
Because other sonatas share some of these features, the paper should apply broadly, and I hope usefully, to C.P.E. Bach scholars and to scholars of eighteenth-century music generally.