The Concerto #13 in C major, K415 presents itself as a dialog between orchestra and piano virtuoso. The orchestral opening of the first movement is written in a military tone with a broader scope than the previous concerto, and the solo sections are sharply distinguished.
Mozart gives the soloist plenty of room to show proof of her/his dexterity. Of remarkable appeal is the switching between major and minor in the vast second theme played by the piano. A brief theatrical effect is exercised by a recurring rocket-like unison rise, appearing four times in each final section.
Mozart contrasts the opening movement with an unpretentious romance in F major in which almost endlessly floating cantilenas resound with lovely class and calm.
The wonderful piano cadenza shows us Mozart’s improvisational gift which seems to be infinite.
The finale of the concerto is unique and unconventional despite its logic and craftsmanship. Its innocent rondo theme is struggling to assert itself during the course of the movement, especially since two suddenly occurring C minor adagio sections have a silencing effect. Mozart had originally outlined the C minor theme for the slow movement of the concerto but opted for the lighter F major in its place. He saved the C minor inserts to create dramatic scene changes in the finale.
After the last appearance of the rondo theme, the music seems to be running away, to scatter into the winds; the concerto ends in pianissimo, and nothing remains of the majestic opening C major celebration.
Here is Mitsuko Uchida, who studied in Vienna as a young girl, performing and conducting the Concerto #13:
