3. Allegro assai
The Piano Concerto No. 20 in D minor, K. 466, was written by Wolfgang Amadeus Mozart in 1785. The first performance took place at the Mehlgrube Casino in Vienna on February 11, 1785, with the composer as the soloist. A few days after the first performance, the composer’s father, Leopold, visiting in Vienna, wrote to his daughter Nannerl about her brother’s recent success: “[I heard] an excellent new piano concerto by Wolfgang, on which the copyist was still at work when we got there, and your brother didn’t even have time to play through the rondo because he had to oversee the copying operation.” It is written in the key of D minor. Other works by the composer in that key include the Fantasia K. 397 for piano, Requiem, a Kyrie, and parts of the dark opera Don Giovanni. It is the first of two concertos written in a minor key (No. 24 being the other).
The young Ludwig van Beethoven admired this concerto and kept it in his repertoire. Famed conductor Daniel Barenboim contends that this concerto was Joseph Stalin‘s favorite piece of music. Cadenzas for this popular concerto written by famous composers include Beethoven (WoO 58), Johannes Brahms (WoO 16), Johann Nepomuk Hummel, Feruccio Busoni and Clara Schumann. The concerto is scored for solo piano, flute, two oboes, two bassoons, two horns, two trumpets, timpani and strings. As is typical with concertos, it is in three movements:
The first movement starts off the concerto in the dark tonic key of D minor with the strings restlessly but quietly building up to a full forte. The theme is quickly taken up by the piano soloist and developed throughout the long movement. A slightly brighter mood exists in the second theme, but it never becomes jubilant. The timpani further heightens the tension in the coda before the cadenza. The movement ends on a quiet note.
The ‘Romanze’ second movement is a five-part rondo (ABACA) with a coda that begins brightly with a strong B-flat major melody. The second episode (part C) is galloping section in the relative minor key of G minor which greatly contrasts the peaceful mood of the rest of the movement. The final movement, a rondo, begins with the solo piano rippling upward in the home key before the full orchestra replies with a furious section. (This piano “rippling” is known as the Mannheim Rocket and is a string of eighth notes (d-f-a-d-f) followed by a quarter note (a). A second melody is touched upon by the piano where the mood is still dark but strangely restless. A contrasting cheerful melody in F major ushers in not soon after, introduced by the orchestra before the solo piano rounds off the lively theme. A series of sharp piano chords snaps the bright melody and then begin passages in D minor on solo piano again, taken up by full orchestra. Several modulations of the second theme (in A minor and G minor) follow. Thereafter follows the same format as above, with a momentary pause for introducing the customary cadenza. After the cadenza, the mood clears considerably and the bright happy melody is taken up this time by the winds. The solo piano repeats the theme before a full orchestral passage develops the passage and thereby rounding up the concerto with a jubilant D major finish.