Never Trust The Surface: K. 333

I’m looking at four deceptively simple measures of the opening theme of the K. 333. As part of a sentential theme, the four measures comprise the basic idea and its repetition at the fifth. There are a number of questions we can ask of ourselves when we hear this music:

• Does the pickup measure represent a proper function, and if it does, what? I’ve interpreted it as Dominant, but just as easily we can hear it as Dominant-Prep.

• The four sixteenths figure in the pickup measure appears again at the tail end of measure two; should we treat it the same way we do at the beginning?

  • As an aside: if the opening pickup is Dominant-Prep, we’re most likely assuming the figure represents a chord built on C. Following the same logic, the return of the figure in measure two would assume a chord built on tonic. Together, then, the sequence of the figure would be (functionally): DP—T, T—D. We could associate the same functional relationship, but reversed, between the bass motion: C down to F (5th like T—D), F up to B♭ (4th like DP—T). This is not necessarily a strict 1:1 comparison, however, since a Dominant-Prep to Tonic relationship can encompass a fourth (E♭ down to B♭) and a second (C down to B♭). I’m very much splitting hairs with these distinctions and by no means am the first to do so: Rameau’s double emploi idea was constructed to tackle this very issue.

• How important are the appoggiaturas/suspensions that appear on the downbeats of each measure?

• Why does G appear in the first measure? Is Mozart “really” after a submediant chord or is it meant to be something else?

Mozart Piano Sonata in B♭, K. 333 mm. 1–4