Symphony No. 41 "Jupiter", K. 551: IV. Molto allegro

The finale of the Jupiter Symphony is an act of audacity — Mozart constructing, in real time, a cathedral of counterpoint that builds from separate voices into a towering simultaneity of five independent themes sounding at once in the final pages. The movement opens with four notes of Roman simplicity, a plain fanfare figure, and you would not guess from its modest beginning what the movement intends. Gradually the material accumulates, fugal writing interweaving with lighter passage work, the textures thickening without losing clarity, until the culminating passage where all the themes sound together in polyphonic triumph — a feat of compositional architecture that has astonished musicians for two centuries. The energy throughout is enormous but controlled, the orchestra moving with the precision of a machine and the feeling of something completely alive. There is joy here, but not the simple joy of the *Nachtmusik* — this is the joy of mastery, of a mind operating at its absolute limit and finding that the limit is higher than anyone imagined. Mozart was thirty-two when he wrote this. He would live two more years. The name *Jupiter* was not his, added by an impresario, but it fits: this is music that feels like it contains its own universe.