AKA modulation and secondary dominants
First, let’s start with the title: Chromaticism. Up until now, we’ve only been looking at chords that don’t need any extra sharps or flats, once we determine what key signature we should be using, known as diatonic harmony. However, most classical music uses some sharps or flats at least part of the time, and many pieces emphasize more than one key on some level at various points. Using notes outside the key signature is known as chromaticism. Chromatic notes that don’t effect the chords (turns, melodic embellishments) are called chromatic non-chord tones.[*] These are fairly common, but since the point of this blog is harmony and chords, we’re going to move straight into the next two types: modulation and tonicization.
Modulation is when the local tonic of the music changes to a different chord, long enough to have a cadence (usually). Tonicization is when there are only one or two chromatic chords emphasizing another chord as if it were tonic.
If you think back to the Bach Prelude we used to look at numbers (here: https://functionalanalysis.blog/2017/01/19/lesson-4-numbers/ ) you’ll remember that I just labeled chords there, and left out some other ideas. Here’s a more complete version, using diatonic substitutes, modulation, and chromatic non-chord tones on the dominant pedal[†]:
You’ll notice in the first system there are two lines of chord analysis. The second line is where it is heard/understood as in G major instead of C major, and where there are chord labels on both levels, those chords can be understood in both keys. This is called a pivot chord. In the second system, the key returns to C major.
You’ll also notice the double-D symbol in measure 6. This is a symbol for Dominant of the dominant, also called double dominant.[‡] Double dominants can also be missing their roots, as seen in measure 22. So, in this key a Dominant is a G major chord, so the dominant of G is D major. This is one of the most basic tonicizations, and double dominants are easy to spot with the solfège fi and a resolution to Dominant.
In measures 12, 20, and 33, a D appears inside parentheses. This is to indicate Dominant of a chord other than dominant. In each case, the chromatic note is a sharp acting as a local leading tone, pulling to the “tonic” in the next chord OR there is a flat acting as a seventh or ninth pulling down in the opposite directions. Generally, chromatic notes will resolve in the direction they are going – sharps up, flats down.
Any major or minor triad can be tonicized. Typically we start with closely related keys: those keys having either one more or less sharp or flat than the key signature. So for C major, closely related keys are G (one sharp), F (one flat), and their relative minors: a minor, e minor, and d minor. These are usually also the first chords we see tonicized.
Next time: Chromaticism using borrowed chords.
Diatonic Harmony: staying within a given key signature/using only the given 7 pitches. Usually includes using the 2 flexible scale degrees ( le/la, te/ti ) when in minor, but may depend on who you ask.
Chromaticism/Chromatic Harmony: using chromatics/accidentals – flats and sharps outside the key signature.
Modulation: a change of tonic. Usually includes a cadence. Look for scalar leading tones or important chordal sevenths to indicate a change.
Tonicization: a momentary emphasizing of another chord as if it were tonic. Look for scalar leading tones or important chordal sevenths to indicate a change.
Dominant Pedal: type of prolongation changing “chords” or notes not in the dominant chord over a sustained dominant pitch in the bass. Used to create anticipation for coming tonic. Named thusly because of organ pedals being the bass notes. (Other notes can be pedaled/sustained, dominant is just the most common.)
Pivot Chord: a chord that can be named logically in two keys. Used to show how a modulation is happening.
Double Dominant: Dominant of the dominant. In C major, D major. Includes fi, sometimes known as Pr with raised third, but we’re focusing on the resolution to a following dominant.
Closely related keys: Keys with one more or less sharp or flat. Most common keys used for modulation in certain eras of music, and the keys that pivot chords are used for modulation.
[*] Since we haven’t been discussing melodic issues quite so much on this blog, I haven’t covered the various types of non-chord tones. Additionally, with numbers the way we used them in lesson 4, we can describe non-chord tones in relation to the root of the current chord more easily than some other systems.
[†] a type of prolongation over a static bass note, commonly used as a way of creating suspense and anticipation for the coming tonic.
[‡] I’ve put it here to show what it looks like; normally we wouldn’t pivot on a double dominant unless we didn’t have a chord that made more sense.