The Vancouver Chopin Society has a beautiful description of Chopin's Preludes, created during his disastrous winter of 1838/39 in Majorca, when Chopin was also studying - and editing - the Well-Tempered Clavier by one of his musical heroes: Johann Sebastian Bach:
Within these very small frames, Chopin captures a universe of feeling and mood. There is a prelude for each major and minor key; many of them demand high virtuosity. James Friskin writes, "Perhaps no other collection of piano pieces contains within such a small compass so much that is at the same time musically and technically valuable." Schumann thought them "eagle's feathers, all strangely intermingled. But in every piece we find his own hand-Frederic Chopin wrote it. One recognizes him in his pauses, in his impetuous respiration. He is the boldest, the proudest, poet-soul of his time." Finck feels that "if all piano music in the world were to be destroyed, excepting one collection, my vote should be cast for Chopin's Preludes. There are among Chopin's preludes a few which breathe the spirit of contentment and grace, or of religious grandeur, but most of them are outbreaks of the wildest anguish and heart-rending pathos. If tears could be heard, they would sound like these preludes."
Besides the famous series of 24 Preludes from Op. 28, there is one more and entirely separate Prelude by Chopin: The Prelude in C-sharp minor, Op. 45, described by the Vancouverites as "a seldom played work of great improvisational beauty. The composition contains far-flung modulations and needs imagination for its presentation."