Composed in the early 20th century, from 1902 to the following year, it was published in 1903, the year of its completion, and premiered by Rachmaninoff himself in February of that year.

Chopin's Prelude in C minor, Op. 28, No. 20, followed by 22 variations. Notably, the first edition of the score states that Variations 7, 10, and 12 may be omitted at the performer's discretion. Furthermore, the "Presto" section that concludes the piece may be omitted, and instead, the piece may end by playing the tonic chord of C minor, the main key of the work. Unlike the Second Sonata, no revised edition of this work, reflecting these comments, has been published.

The theme is in C minor, 4/4 time, Largo. This theme does not directly use Chopin's original but has been shortened.

Variation 1 becomes Moderato, and the original melody is quickly embedded within a single line full of ornamental notes. Here, Rachmaninoff constructs the first four measures solely with such a line, and in the remaining five measures, he presents a thin texture by sustaining the low C (tonic) for a long duration.

Variation 2 becomes Allegro. The line played by the right hand in Variation 1 shifts to the left hand. Here, the first note of each measure within the melody played by the right hand above it is not performed. In this way, the theme's phrase is skillfully handled.

In Variation 3, with the Allegro tempo maintained, the left and right hands play music as if two threads weaving together.

In the subsequent Variation 4, the time signature changes to 3/4. Its scale also becomes somewhat larger, spanning 24 measures. The theme begins ff, but prior to this, from Variation 1 to Variation 3, the dynamics were primarily p or pp. In contrast, in this Variation 4, a dynamic climax is systematically built.

Then, in Variation 5, the time signature returns to 4/4, and the tempo becomes Meno mosso.

Variation 6 becomes even Meno mosso. Here, in 6/4 time, the right hand's sextuplets and the left hand's nonuplets exhibit polyrhythm. Furthermore, from the latter half, arpeggiated chords are played on the beat.

Variation 7, as mentioned, can be omitted. Here, it becomes Allegro, and both hands cooperate to play lines of small note values filled with additional notes.

Variation 8 is marked with the same tempo as Variation 7. Therefore, if Variation 7 is omitted, it becomes Allegro from this point. This variation also features polyrhythmic playing by both hands, but here it is marked leggiero.

Variation 9 also continues with the same tempo. Here, a characteristic Rachmaninoff technique is seen, where two registers are played alternately, and the music develops through their interplay.

Variation 10, as mentioned, can be omitted. Here, it becomes Più vivo, and the theme is treated in a manner close to a canon. At the end, the tonic chord of C minor rings out ff, with a fermata placed upon it.

In the following Variation 11, the tempo abruptly changes to Lento in 12/8 time. Therefore, whether Variation 10 is omitted or not significantly alters the overall flow of this work. Here, the theme is treated very chromatically. Tempo changes, marked by ritardando and a tempo, are prominent.

Variation 12, written in Moderato 4/4 time, can also be omitted. A 2/4 measure is inserted midway through this section. Such subtle changes in time signature, even within a very small scope, are also characteristic of Rachmaninoff's technique. And because the music develops dramatically within this variation, similar to Variation 10, omitting or including Variation 12 significantly alters the overall flow of this work.

In the next Variation 13, it becomes Largo in 3/4 time. Here again, similar to Variation 9, a characteristic Rachmaninoff technique is seen, where two registers are played alternately, and the music develops through their interplay.

Variation 14 is written in Moderato 4/4 time. Here, the theme is treated as a dynamic scale. Instructions are given to clearly emphasize the melody. Also, the last measure of this variation is written in 2/4 time, leading into the next variation, which is in 12/8 time.

In Variation 15, it modulates to F minor, the subdominant key relative to the main key, and becomes Allegro scherzando. This variation is written polyphonically. It is also relatively large in scale, becoming Più vivo near its conclusion.

The subsequent Variation 16 is also written in F minor and becomes Lento. Here, the melodic phrasing is brought under Rachmaninoff's control, treated with a rhythm akin to transcribed rubato.

In the next Variation 17, it becomes B-flat minor, which is the subdominant key relative to F minor. Also, here it becomes Grave in 3/4 time. The rhythm is predominantly based on eighth notes, with two measures of inserted triplets proving effective.

Variation 18 continues to be written in B-flat minor. However, it becomes Più mosso in 4/4 time. Here again, music based on polyrhythm unfolds.

Then, in Variation 19, it abruptly modulates down a semitone to A major. This section, written in Allegro vivace 4/4 time, is characterized by a very thick chordal texture.

Furthermore, in Variation 20, the key changes contribute to the dramatic progression of the music. The key signature of this variation, written in Presto, has four sharps. It generally progresses from C-sharp minor to E major and back to C-sharp minor, beginning with the tonic chord of A major from the preceding Variation 19. In the E major section, passages of small note values in the high register, characteristic of other Rachmaninoff works, are like a momentary flash of light.

The subsequent Variation 21 begins in D-flat major, the enharmonic equivalent of the parallel major. This variation also progresses very dramatically. The initial Andante section is followed by a Più vivo section. This section has no key signature, but as G is emphasized, it is considered to sustain the dominant of C major.

And Variation 22, which concludes the entire work, is written in C major. Therefore, the preceding Più vivo section must have sustained the dominant of C major, thus serving as a bridge to this section. It also becomes clear that the latter half of the work has traversed through highly dramatic keys before arriving at the parallel major of the work. This variation is written in Maestoso 3/4 time and is spun out on a relatively large scale using various techniques seen thus far, such as thick chordal textures, polyrhythms, and the development of music through the interplay of two alternating registers. As mentioned earlier, the Presto section after the Meno mosso may be omitted, and instead, the piece may conclude by playing the tonic chord of C minor, the main key of the work.