Why is the finale of Mozart’s Jupiter Symphony notable for its fugal writing?

The finale of Wolfgang Amadeus Mozart’s Jupiter Symphony (Symphony No. 41 in C Major, K 551) is considered a unique tour de force in music history because it masterfully integrates complex fugal procedures within a sonata form movement.12

While Mozart employed fugal techniques only seldom in his instrumental works, he utilized them here with conspicuous success. The movement is notable for its:1

• Fugal Complexity: It features extensive passages of fugato—a compositional technique where a fugue-like subject is introduced and developed—culminating in a grand apotheosis.12
• Invertible Counterpoint: The finale is specifically celebrated for its use of five-voice invertible counterpoint, a highly sophisticated method of arranging melodic lines so that they can be transposed and rearranged while maintaining harmonic correctness.12

This synthesis of rigorous contrapuntal tradition with the structural demands of the Classical symphony solidified the work's reputation as a masterpiece, earning praise from later composers like Robert Schumann, who famously noted that there was simply nothing to be said about such a work.3