There are some 27 piano concertos by Mozart. The first one of any importance is concerto number nine in E-flat, K 271. This concerto was composed for a French woman, Mlle Jeunehomme. Charles Rosen, a man whom I respect greatly, calls this concerto the first masterpiece in the classical style. The first movement is unusual for introducing the piano right at the beginning, after an extremely brief orchestral fanfare. A concerto first movement generally has a long orchestral introduction before the soloist is heard. The first movement of this concerto proves that at the age of 21, Mozart already had mastered the art of composing a piano concerto. The second movement is a poignant andantino in C-minor. The finale is a happy rondo with a minuet for one of its episodes.

Concertos number 14 in E-flat, K 449, number 15 in B-flat, K 450, and number 16 in D major, K451, are all three worthy of note. In these three concertos Mozart’s treatment of the orchestra, especially the wind instruments, surpasses anything he had done before. Mozart freed the wind instruments from merely doubling the strings, and gave them many interesting melodic phrases of their own. He was original and inventive in his treatment of winds in piano concertos long before he was in the symphony. In fact, in no other genre of music did he so skillfully use wind instruments. He also went far beyond anyone before him in the way he treated the piano and the orchestra as equal partners in a dialog. Mozart did not invent the piano concerto, but was the first composer to write great ones, and wrote more great piano concertos than anyone. He developed the genre from its simple beginnings into something truly momentous.

Piano concerto number 17 in G major, K453, was composed for a female pupil of his. This work is, in my opinion, one of Mozart’s finest concertos. Its first movement begins with a theme in a march-like rhythm. Again the winds are used to great effect. The gaiety of this movement is tinged here and there by excursions into minor keys. The slow movement is a beautiful andante in the key of C major that is also tinged by excursions into minor keys. The finale is not a rondo as would be expected, but is a set of variations. The theme is a lively bouree. Its minor key variation to my ear sounds rather mysterious.

Piano concerto number 18 in B-flat, number 18, K456 is not one of his better concertos. It is certainly not bad. One would be hard pressed to find anything by Mozart that can be called bad, but it is not one of his greatest works by any means.

Piano concerto number 19 in F, K 459, is a good work. It is not one of my personal favorites, nor is it one of his most popular concertos, but it does not fail to please. I find the finale more satisfying than the first two movements.

Piano concerto number 20 in D minor, K466 is one of Mozart’s most popular concertos. Mozart seems quite often to have associated the key of D minor with a dark foreboding atmosphere, or a threatening or vengeful feeling. There are good examples of this in Don Giovanni and in The Magic Flute. This concerto is no exception. The first movement begins with the strings pulsating softly on a D minor chord with the bass playing short, upward scale passages that have a threatening or foreboding character about them. This first movement is full of passion and violence. There is nothing akin to it in any other Mozart concerto. The unrelenting darkness is unusual for Mozart. He usually balances darkness with light, violence with gentleness. But here there is no letting up. A few brief measures here and there hint of a softer, more gentle emotion, but they are quickly swept aside by another violent outburst. This concerto, particularly the first movement, was to become a big influence on Beethoven.

The slow movement to K466 is in B-flat and has a lovely melody for its main theme. After a powerful, stormy outburst in G-minor, it returns to B-flat and the main theme is heard again. A very pretty coda rounds off the movement.

The finale to K466, like most Mozart finales, is a rondo. It begins with the solo piano and this is quickly answered by the full orchestra. It establishes the key of D-minor immediately, but goes through several other keys before returning to D-minor. After the cadenza the oboes, bassoon, and horns begin playing in D major. The piano soon takes over and then the whole orchestra joins in. The movement remains in the key of D major until the end.

Concerto number 21 in C major, K467, is another concerto of Mozart’s that has become very popular. The first movement of this concerto opens up with a march-like theme, played softly by the strings. It has a rather majestic, regal feel to it as so many of Mozart’s C major first movements do. The second movement is a beautiful andante in the key of F. This movement is one of Mozart’s most beautiful movements in any genre of music. The finale is a hybrid of sonata and rondo forms. It is lively and happy and rounds off this concerto perfectly.

Concerto number 22 in E-flat major, K482, is not one of the more popular concertos by Mozart. It is a good work, but not in the same league as his truly great works.

Concerto number 23, in A major, K488 is one of only a handful of works by Mozart in the key of A major. One thing that can be said of this concerto is that it is very pretty throughout. All three movements are melodic and graceful. In my opinion the slow movement is one of Mozart’s most beautiful. Whereas the first two movements, ostensibly happy, are not untouched by an undercurrent of melancholy here and there, the rondo finale is happy and exuberant throughout, without a tinge of sorrow. It is one of Mozart’s best finales. It is happy and cheerful. It has a sort of perpetual motion that refuses to die until the last bar.

Concerto number 24, in C-minor, K491 is one of only two piano concertos by Mozart that are in a minor key. This is the one that the critics acclaim as being Mozart’s best concerto. This is the one that Beethoven was so deeply impressed by.

It can almost be called a concerto for piano and winds because it has so many concertante parts for the wind instruments. This concerto is the only one of Mozart’s piano concertos with both oboes and clarinets.

The opening movement is so serious, so austere and so powerful. Mozart’s Viennese audience, so used to his lyrical happy melodies, must have been somewhat taken aback by this first movement. It is so serious! So profound! Charles Rosen points out that the first movement of this concerto has a certain similarity to Haydn’s symphony number 78. Listening to the Haydn symphony, anyone can see the similarity of the beginning, but Mozart’s opening theme is more expansive. It begins with the strings and bassoon in unison, playing a rather disjunct chromatic theme. Suddenly the entire orchestra plays forte. The irregular phrasing and the concentration on small motifs are unusual for Mozart, who usually uses full-blown melodies as themes. This movement is so passionate, so powerful, so carefully crafted and with rich inner part writing. No wonder Beethoven was so inspired by it.

The second movement is the only conventional movement in this concerto. It is based upon a rather pretty melody and has little pretension of complexity.

The finale of the C-minor concerto is unusual for being a theme-and-variations movement. The theme is given out by the orchestra and the piano immediately spins out the first variation of it. There are eight variations in all, followed by a coda. This is truly a masterpiece concerto.

The concerto number 25, in C major, K503 has the longest first movement of any Mozart concerto. It may be the longest first movement in Mozart in any genre of music. This opening movement is very majestic and powerful, like certain other pieces in C major by Mozart. With two horns and two trumpets, it is strongly colored by a brassy sound. It opens with the entire orchestra playing forte on the chord of C major. Only seventeen measures into the piece it goes into the key of C minor with oboes and bassoons playing a short motif in parallel thirds, first the oboes, then the bassoons. Then the oboes, then the bassoons again. The strings quickly take up a theme that rises and rises until the entire orchestra plays a C major chord forte and a sequence of scale passages rises higher and higher, generating immense excitement. The music is in the key of G for a page or so, and then is back in C minor. After eight measures of C minor, we are back in C major. After a few more pages of orchestral music, the piano enters, plays solo for several measures, then plays along with a light accompaniment. Then suddenly the music of the opening is repeated, this time with the piano adding to the powerful orchestral music. This movement is so powerful and large, but it never loses focus, and it is perfectly balanced in its proportions.

The slow movement is a lovely andante in the key of F major. It is colored by frequent excursions into minor keys. It is sumptuous and long.

The finale is a rondo whose main theme is a gavotte that Mozart had used five years earlier in the ballet music to his opera, Idomeneo. This rondo is not of the happy-go-lucky type that ends some of Mozart’s concertos. It sounds a bit more serious, but is certainly not without passion. As usual for Mozart, this rondo is tinged by excursions into minor keys, but not to the extent of the first two movements.

Concerto number 26, K 537, is known by the nickname “Coronation concerto” because Mozart showed up, unannounced and uninvited, and played it at the coronation ceremony of Emperor Leopold II.

In the scores of most of Mozart’s piano concertos, the piano part is rather sketchy. This is not true for the concertos that he composed for other performers. The piano parts in those concertos are written our thoroughly and carefully. Mozart composed most of the piano concertos for his own performance, and the piano part was not fully written out. Mozart embellished what he had written on paper and probably never played the same concerto twice in the same way. Concerto 26 is the most sketchy of all. The piano part is a mere skeleton which Mozart would have enriched upon quite a bit during performance. It seems he must have been in a big hurry when he wrote it and didn’t spend a lot of time writing the piano part. This creates a problem for performers. The pianist either needs to be good at improvising or he or she needs to use a score in which someone has added to the sparse piano part in the original. This is not one of his most popular concertos, but it is a good work, perhaps not great, but still very good.

Now we come to the last of the Mozart piano concertos, number 27 in B-flat, K 595. This one was finished about three weeks before his thirty-fifth birthday, and was to be his last. He had only eleven more months to live.

The first movement of this concerto is very pretty, and like much of the music of Mozart’s last year or two, the happiness is mitigated by a dark undercurrent of sorrow. More than in any of his other concertos, Mozart abandons pianistic virtuosity, and instead, seeks a blend of piano and orchestra as equal partners. All three movements of this concerto are beautiful and sweet. Though not generally thought of by the critics as being as great as certain other concertos, notably numbers, 20,24, and 25, this concerto is very well crafted in its proportions, its parts, and its orchestration, and is a very beautiful work.

In conclusion I would like to say that Mozart was the king of the piano concerto. Others after him composed masterpiece concertos but he composed more piano concertos than anyone, and all of them from number 9 onward are of very high quality, and a few of them are awesome masterpieces.