Wolfgang Amadeus Mozart had a way with the piano concerto, like no other composer before or after him. Building upon the achievements of two of J.S. Bach’s sons, Carl Philipp Emanuel and Johann Christian, Mozart gave the word “concerto” a whole new meaning and set expectations not just in the minds of his own audiences, but for generations to come. He continued the idea of alternating orchestral and solo passages, but also completely expanded on the earlier form, making it both more complex and more flexible. In his hands, the piano concerto became capable of expressing diverse characters and feelings, from grandiose and festive to lyrical and intimate, with innumerable shadings in between. 

Throughout the 1780s, Mozart wrote several concertos each season, which he premiered to great acclaim. What we now know as Piano Concerto No. 23 — the group was cataloged and numbered decades after Mozart’s death — was written in 1786, the year Mozart completed his opera The Marriage of Figaro. 

The first movement of this concerto does not open with a fanfare or powerful “curtain-raising” motive, as many other concertos do. It begins instead with a gentle melody, setting the stage for a movement with a unique blend of moods. Here we experience a quiet serenity with occasional touches of wistfulness. In the orchestration, one notes the absence of oboes and the presence of clarinets, resulting in a special, darker-hued sound. Before long, the strings introduce a new theme that is immediately embellished by the piano and later elaborated upon by the orchestra. 

For many of Mozart’s concertos, we do not have a solo cadenza written in the composer’s hand. Most often, he left this part of the score blank and improvised in performance. For the first movement of this concerto, however, an original cadenza by Mozart has survived. This cadenza tells us a great deal about Mozart the improviser. Besides virtuosic passages, it also contains expressive, singing music and expands upon the concerto’s thematic material in simple yet ingenious ways. 

The Adagio movement is extraordinary even among the other slow movements of Mozart’s mature piano concertos. Its dominating sentiment in many ways presages musical Romanticism. The melody moves in the quiet rhythm of the siciliano dance, but contains many wide, expressive leaps, emphasizing chromatic half-steps and melancholic chords. The key of F-sharp minor is extremely rare in Mozart’s music — in fact, this is the only time it appears as a movement’s main key in the composer’s entire catalog. The unusual quality of the key gives the music a certain heightened poignancy that is easier to feel than to describe. 

The third-movement finale, marked Allegro assai, is a playful romp with a multitude of spirited melodies. It is an extended “sonata-rondo,” meaning that a recurring theme (rondo) alternates with a number of episodes but one of the episodes also returns, just as a second theme would in a sonata form’s recapitulation. The fusion of these two forms results in a structure that allows us to enjoy the wonderful melodies several times, while the alternations and transformations of the melodies afford a seemingly inexhaustible diversity. 

Mozart was well aware of the exceptional richness of this concerto. It was one of a select group of works he sent to Prince Fürstenberg in Donaueschingen. In an accompanying letter to Sebastian Winter, a former servant of the Mozart family who later worked for the Prince, the composer wrote that these were “compositions which I keep for myself or for a small circle of music-lovers and connoisseurs (who promise not to let them out of their hands).” He wanted the Prince to be assured that these compositions had not been circulating widely and did not hide his hopes for future commissions. Mozart received a total of 143.5 florins for the scores he submitted (four symphonies, five concertos, and three chamber works), which covered approximately three months’ rent at his Vienna apartment. However, the additional commissions Mozart hoped for never materialized. 

— Peter Laki 

Peter Laki is a musicologist and frequent lecturer on classical music. He is a visiting associate professor at Bard College.