The Rondo, more often than not, is the form used in the last movement of a Classical era Sonata. (The Classical period roughly encompasses the years between 1750 and 1830) The Rondo is usually a brisk, lively and energetic movement that brings a sonata to a definitive conclusion. It is in the home key of the piece.
In the Sonata, K. 545, Mozart composes a light-hearted final (third) movement evocative of the Opera Buffa, or comic opera.
Form: A B A C A Coda
The “A” section, or Rondo in the bright C Major tonality, with a two eighth note short upbeat to a slightly more prolonged 8th note downbeat is the basic motif of the movement, and will come back interspersed with a B and a C section. The “B” section is in the Dominant key of G Major, while the “C” section goes into the Relative minor ( A minor) This A minor section has a Development-like character, and is more prolonged as it delightfully meanders and then winds its way back to the Rondo “A” section that is in the home key of C Major.
In the A minor or “C” section, Mozart uses an inversion of thirds to 6ths, and dances from one hand to the other, with inverted counterpoint. (He flips over the voices, so that the listener experiences the motif or Rondo idea in the bass range, with a 16th decoration in the Treble and in reverse) The devices of inverted intervals and inverted counterpoint are significant characteristics of this “C” section of the final movement.
Through a pivot chord, using A minor, as a double identity Vi chord in C Major going to its Dominant, G B D, the movement weaves its way back to the “A” section Rondo in C Major followed by a Coda (added concluding section) using Dominant and Tonic progressions in broken chord fashion to the very last splash of articulated, unisons that bring the movement to a resounding, and definitive ending. At the end of this work, I feel like I’m in the orchestra pit, conducting those last measures as the curtain goes down in the opera.
Feedback is always appreciated. If you have ideas to share about this effervescent movement, please post.
Links to Piano Instruction first movement (in three parts)
Second movement, Analysis and Instruction: