inserted an E flat at the end of bar four, thus maiming the tender, elusive quality of Chopin’s theme.  This is cruelly pedantic.  The prelude arrests one in ecstasy; the fixed period of contemplation of the saint or the hypnotized sets in, and the awakening is almost painful.  Chopin, adopting the relative minor key as a pendant to the picture in B flat, thrills the nerves by a bold dissonance in the next prelude, No. 22.  Again, concise paragraphs filled with the smoke of revolt and conflict The impetuosity of this largely moulded piece in G minor, its daring harmonics,—­read the seventeenth and eighteenth bars,—­and dramatic note make it an admirable companion to the Prelude in F minor.  Technically it serves as an octave study for the left hand.

In the concluding bar, but one, Chopin has in the F major Prelude attempted a most audacious feat in harmony.  An E flat in the bass of the third group of sixteenths leaves the whole composition floating enigmatically in thin air.  It deliciously colors the close, leaving a sense of suspense, of anticipation which is not tonally realized, for the succeeding number is in a widely divorced key.  But it must have pressed hard the philistines.  And this prelude, the twenty-third, is fashioned out of the most volatile stuff.  Aerial, imponderable, and like a sun-shot spider web oscillating in the breeze of summer, its hues change at every puff.  It is in extended harmonics and must be delivered with spirituality.  The horny hand of the toilsome pianist would shatter the delicate, swinging fantasy of the poet.  Kullak points out a variant in the fourteenth bar, G instead of B natural being used by Riemann.  Klindworth prefers the latter.

We have reached the last prelude of op. 28.  In D minor, it is sonorously tragic, troubled by fevers and visions, and capricious, irregular and massive in design.  It may be placed among Chopin’s greater works:  the two Etudes in C minor, the A minor, and the F sharp minor Prelude.  The bass requires an unusual span, and the suggestion by Kullak, that the thumb of the right hand may eke out the weakness of the left is only for the timid and the small of fist.  But I do not counsel following his two variants in the fifth and twenty-third bars.  Chopin’s text is more telling.  Like the vast reverberation of monstrous waves on the implacable coast of a remote world is this prelude.  Despite its fatalistic ring, its note of despair is not dispiriting.  Its issues are larger, more impersonal, more elemental than the other preludes.  It is a veritable Appassionata, but its theatre is cosmic and no longer behind the closed doors of the cabinet of Chopin’s soul.  The Seelenschrei of Stanislaw Przybyszewski is here, explosions of wrath and revolt; not Chopin suffers, but his countrymen.  Kleczynski speaks of the three tones at the close.  They are the final clangor of oppressed, almost overthrown, reason.  After the subject reappears in C minor there is a shift