Third Relations & Pantriadicism
Both diatonic and chromatic melodies can be effectively harmonized with chord progressions that deliberately avoid the common patterns of harmonic progression used in classical music.
Third Relations
In an otherwise tonal piece, a composer can create a temporary sense of freedom from a particular tonal center by moving through a string of chords whose roots are M3 or m3 apart. This technique, called third relations or chromatic mediants, gives the piece a sense of weightlessness, allowing a shift to an unrelated key.
Pantriadicism
The harmonic distance in a third relationships passage can be illustrated using the circle of fifths: a root movement of a m3 moves three steps away on the circle, and a root movement of a M3 moves four steps away.
By juxtaposing unrelated chords — chords which are far from one another on the circle of fifths — composers can create a harmonic texture very different than the traditional harmonic patterns used in the Common Practice Period. This type of harmonic approach is called pantriadicism.
Like third relations, pantriadicism can be effective in suspending tonality within a tonal work.
Pantriadic chord sequences can be effective in a chorale texture, and can include smooth voice-leading despite the chords' harmonic distance.
Neo-Riemannian Theory
Because pantriadic harmony specifically avoids tonal harmonic function, theorists do not use Roman numerals when analyzing these passages, even if the chords themselves might occasionally align with the global key area. Instead, theorists will generally label chords in a pantriadic section with harmonic macroanalysis, and track the harmonic distance between each chord.
A commonly used system for measuring how related one chord is to another is neo-Riemannian theory, named for German music theorist Hugo Riemann. Neo-Riemannian theory is based upon triad transformations, accomplished by changing one of a major or minor triad's three notes to create a different major or minor triad.
The three primary transformations in neo-Riemannian theory are:
- Parallel transformation (P), accomplished by moving a triad's third by a half-step to change it from major to minor or vice versa;
- Relative transformation (R), accomplished by moving a major triad's fifth up a whole step to create a minor triad, or vice versa;
- Leading-tone Exchange (L), accomplished by moving a major triad's root down a half-step to crete a minor triad, or vice versa.
The Tonnetz
Theorists using neo-Riemannian theory find it helpful to visualize chord relationships using triangles to represent triads, with its three notes at each corner. Triads which share two notes can then be shown as triangles which share a common side. Using this system, the three primary transformations, P, R and L, can be easily seen.
By continuing this pattern in each direction, a grid can be created which neo-Riemannian theorists call the Tonnetz. Like the circle of fifths, the Tonnetz can be extended indefinitely by using double sharps and double flats, triple sharp and triple flats, and so on, but by assuming enharmonic equivalence, only a limited section is necessary.
Neo-Riemannian Analysis
Any music which uses triadic harmony can be analyzed using neo-Riemannian theory by denoting the shortest number of transformations needed to move from one chord to another.
Three common secondary transformations used in neo-Riemannian theory involve the combination of multiple primary transformations:
- Nebenverwandt (N), done by applying R, then L, then P
- Slide (S), done by applying R, then P, then L
- Hexatonic Pole (H), done by applying L, then P, then L again
Third Relations & Pantriadicism: Summary
- Third relations involve moving chords by a consecutive root movements of a M3 or m3.
- Third relations can create an effect of a suspension of tonality, allowing composers to drift out of one key and into another.
- Pantriadicism involves the juxtaposition of chords which are three or more degrees apart on the circle of fifths.
- Like third relations, pantriadicism can be useful in suspending a sense of tonality.
- Pantriadicism can be used in a chorale texture with smooth voice leading.
- Neo-Riemannian theory is a tool for measuring the relationship between two triads.
- In neo-Riemannian theory we observe three primary transformations of a triad:
- Parallel transformation (P): moving a triad's third by a half-step to change it from major to minor or vice versa
- Relative transformation (R): moving a major triad's fifth up a whole step to create a minor triad, or vice versa
- Leading-tone Exchange (L): moving a major triad's root down a half-step to create a minor triad, or vice versa
- The Tonnetz is a useful diagram for envisioning neo-Riemannian transformations.
- In the Tonnetz, each triad is represented by a triangle with the component pitches on each corner.
- Transformations are shown on the Tonnetz by moving from one triangle to another triangle with a shared side.
- Distant relationships between triads are illustrated through multi-step neo-Riemannian transformations.