I. Allegro II. Romance III. Rondo. Allegro assai

Mozart’s Piano Concerto No. 20 – one of only two Mozart concertos, out of 23, written in a minor key. The minor mode had a special meaning for the masters of Viennese classicism, in whose works the choice of this "sad" mode usually goes hand in hand with a heightened sense of drama and a whole set of specific harmonic, rhythmic, and textural devices that we don’t often encounter in compositions written in the major. It is in such works that we may perceive the first signs of musical Romanticism before it became the dominant style of the early 1800s. The D-minor was the only Mozart concerto Beethoven ever performed (he even wrote down the cadenzas he played). It appealed to 19th-century ears more than did any other of the concertos; it reminded listeners of Mozart’s opera Don Giovanni, with which it shares its principal key and its dramatic intensity.

Like most of the piano concertos Mozart composed for his own use in his subscription series in Vienna (a total of 14 works), the D-minor was written in great haste and completed just a day before the performance. Mozart’s father Leopold, himself a composer and violinist, was visiting from Salzburg at the time, and wrote to his daughter Nannerl, a talented pianist and former child prodigy, after the concert: "…Then we had a new and very fine concerto by Wolfgang, where the copyist was still copying when we arrived, and the rondo of which your brother didn’t even have time to play through, as he had to supervise the copying."

The unique character of the concerto is apparent from the start. Whereas most Mozart concertos begin either with a powerful statement for full orchestra or a soft lyrical melody, the D-minor opens with more amorphous material: a syncopated rhythm on a single repeated note that evolves into a recognizable theme only gradually. Syncopations (shifted musical emphases) and chromaticism ("colouring" pitches outside the ones that make up the main key) are two "irregular" musical devices characteristic of the minor mode; they create a special dramatic quality throughout the concerto. The entrance of the solo piano, on a new theme filled with intense pain and longing, adds a new dimension to the emotional range of the movement. The tension is so strong that a coda of unusual length is required after the cadenza before the music can calm down.

The second-movement "Romanza," in B-flat major, is lyrical and peaceful, or so it seems at the beginning. Its G-minor middle section, however, thrusts us right back into the stormy atmosphere of the first movement. The preparation for the return of the initial theme is particularly masterful and atmospheric.

The final Rondo returns once again to the impassioned mood of the first movement, but moves from there to a brighter, more cheerful section in D major, representing, in the words of one commentator, "a victory of serenity over the tumultuous anxiety of earlier moments."