Chromaticism in the Chopin Preludes
The 24 Chopin Preludes, influenced by the WTC of Bach, present a complete suite of short piano works organized around the cycle of fifths in both major and minor. The sequence is C major, A minor, G major, E minor, D major, B minor and so until the final four: Bb major, G minor, F major and D minor. They are all exquisite compositions and great examples of Chopin's explorations of chromatic harmony. Here are a few highlights. I don't need to place musical examples here, as you can refer to your score and also play back the pieces using our Naxos listening library.
Prelude in E minor
This preludes uses what I can only think to call the "chromatic slip down technique." While it would be possible to label all the ensuing chords with function symbols or Roman numerals, few of them would resolve in the way they are "supposed" to resolve. The F# diminished seventh chord in the second half of the second measure, for example, could be called a viiº7/III, except the chord moves into a F7 triad, which is, what exactly?—V7/bIII in the relative major? Similarly the E7 chord in measure 4 would be called a V7/IV in traditional harmonic progressions, but it does not move in any way towards A minor.
The "chromatic slip down technique" is an elaborate way to get from i to V, and to express poignant, "world weariness" at the same time. It is ambiguous harmony in service to a higher poetic purpose.
I must point out an error in the copy. This anthology prints from an old edition, where the chord near the final cadence, just before the fermata over the half rest, is spelled like a C7 chord in third inversion. But in fact, in Chopin's hand, the Bb is spelled as A#, the making this a German 6th chord (C to A# is the augmented sixth, or in this case the diminished third) with the sixth in the bass, resolving in this case "properly" to the dominant of E.
Prelude in B minor
The main point of this Prelude, in reference to our work, is in measures 11 through 14, where there is a clear V7-I cadence in the key of C, except that it never sounds as if C is taking on a tonic function. The C seems to float ambiguously and, as we agreed, is in fact an extended "Neapolitan moment" (albiet with the root in the bass), moving "properly" to the V7 of B minor and back to B minor in the ensuing bars.
This passage also points a delightful use of the mediant chord—G major in relationship to B minor—as a "Dominant seventh of the Neapolitan." Listen to this or play it at the piano, it's a wonderful example of smooth harmonic motion. This is especially effective because in the first iteration of the theme, when we reach the G major triad in measure 5, it is followed by a complex series of chromatic harmonies that swirl around and ultimately reach the Dominant chord of F# major. This is in contrast to measure 11, when this same G major moment opens out onto a pure C major triad. This is good composing, folks!
Prelude in C minor
This is a double use of the Db, Neapolitan relationship. In measure 2, the Db triad is a pivot chord that functions as IV in the brief move to Ab. In the penultimate measure, the same Db chord, in root position, is actually functioning as Neapolitan (bII), moving to V7 and to I. This is a useful progression to learn and understand.
Prelude in E major
The fun starts in measure 5 and never quits. Try to apply the following analysis to what you see on the page. What we discussed in class was as follows (measure numbers in parenthesis).
(5) I and V in E major moves to a G major chord, which is in a mediant relationship to B but also serves as V of C.
(6) The C chord (are we "in C" now?) moves to a modal v (G minor), but then Bb is sustained when the chord returns to C, transforming it into a V7 of F. So are we moving to F? We were just in E a few moments ago.
(7) Hmm, the V7 of F moved to an A major triad, which is another mediant relationship—keep the A, which would have been the third of the intended F triad, but use it as the root of a chord from another key. This is followed by a diminished seventh chord (C#-E-G-Bb) which "should" resolve to D, but doesn't. Instead, the Bb holds, the C# holds and is respelled Db, the E and G move inwards and suddenly we have a Bb minor triad. Then these same two notes, Bb and Db, hold, the rest of the chord shifts around it and we have a diminished seventh chord based on G (G-Bb-Db-Fb). Such a chord is supposed to go to an Ab chord, but, deep sigh, it probably doesn't.
(8) Oh wow, it does go there! He's finally following the rules! He even cadences in Ab. But wait, I thought this was a prelude in E. We're completely on the other side of the cycle of fifths—four flats instead of four sharps! What are we going to do?
No problem, just turn the Ab major triad into an Ab minor triad through modal shift, respell the Ab and the Cb as G# and B, and then through a Mediant shift, you're on the the iii chord in E major, you can walk right back home. Pretty clever stuff.
Take this same process and figure out measures 9 to the end.