Mozart used an orchestra larger than for any of his other piano concertos to that time. The autograph score shows many erasers and corrections, quite uncharacteristic of Mozart as many of his autograph scores were fairly pristine. This concerto was written at the same time Mozart was writing his opera The Marriage Of Figaro. He was the soloist in the first performance of the concerto in 1786, two weeks after he completed it. The concerto is in 3 movements:
I. Allegro - The first movement opens with a quiet, sinister theme that is developed into a roar carried by the rest of the orchestra and piano. Although the theme is in C minor, Mozart uses all the tones in the chromatic scale in it:
There are two secondary themes that help to give some relief to the tension, but the movement is dominated by the opening theme. The drama and tension of most of the movement may lead the listener to be prepared for a stormy end to the movement but the music quietly and abruptly ends.
II. Andante - Music that is in contrast to the turbulence of the previous movement. Mozart was one of the great composers for wind instruments and it shows in this movement as there are extended passages for wind ensemble. There is a feeling to this music akin to what Mozart wrote in some of his serenades, as the piano and winds take turns with the gentle thematic material. The music reverts back to the beginning of the movement and gently winds down to a restful conclusion.
III. Allegro - Presto - Instead of ending the concerto with a movement in the usual rondo form in a lighter mood and a major key, the third movement begins with a theme in C minor that is the basis for a masterful set of variations:
The eight variations contrast one another in mood until the last variation shifts to 6/8 time with an ominous rhythmic lilt that leads to the resounding final chord.
The great French writer André Gide said about Mozart that he speaks in whispers while the public tends to hear only shouts. Comparing Mozart to Beethoven, that is perhaps true. But the 'whispers' in this concerto are dramatic, prophetic of things to come from other composers.