Mozart: Piano Sonata in D Major, K. 284, I

All right, more Mozartian fun with sonatas. The expository section begins right away. The Group I theme begins with a full period. The first four measures bring us to a half cadence, then we have contrasting material to bring us to a PAC in our original key. From here we being our next phrase in the group, which modulates, first with HC in D major which is then followed up by an IAC in A major. The Group II theme begins after a 4 bar transition that helps us modulate into the second major tonal area. Group II is in the key of E (two steps up the circle of fifths). The theme is an assymmetric period, with a 6 bars phrase, followed by a 7 bar one that cadences on an IAC in E. The second theme of this group lasts 10 measures and brings us back closer to our original key, ending on a HC in A, before a closing 8-bar phrase that ends with a PAC in A. As is the usual sonata way, the whole section repeats. As we enter the developmental section we reintroduce the second half of the Group I theme and expand it in the parallel minor key. We cycle through keys quickly, sequencing up the scale, then back down. The section is relatively short and ends with a long monophonic scalar passage that brings us right back the recapitulation. The recapitulation is in our original key (odd) but ingeniously when we transition twe only go up on degree of the circle of fifths and tada, end up back at our original D major (since by the end of the second theme we modulate back down a fifth). The closing theme adds a cadential extension this final time, ending in a great big PAC to end the piece.