An Introduction to the Basics of Jazz Harmony
By Zubin Edalji, © 2021
What are sonorities?? “Sonorities” roughly translates to "sound-world".
Each sonority is a unique sonic world, color, emotion, etc. Technically speaking, sonorities are the result of a particular root, or bass note, interacting with a particular quality.
Root (bass note)
Sonorities are strung together to create chord-progressions or “chord-changes”.
There are many common types of chord-progressions. Musicians instantly know them, and have techniques for improvising over them. Common progressions can be as short as two or three sonorities (as in the 2-5-1 progression) or they can cover an entire tune/composition, like John Coltrane's "Giant Steps" progression.
Composers string common progressions together with more personalized ones to create a basic form or structure of sonorities that jazz soloists will "blow" or improvise over, usually after they play the melody to a tune. Usually, the chord-progression for the solos is at least loosely connected to that of the melody.
During the solo, the improvisor essentially becomes a composer, but within the universe of the chord-progression.
More experienced soloists may improvise music that departs from the chord-progression at times by superimposing alternate sonorities over the original ones. For the most part this is pretty scientific. There is method and practice involved with what becomes the art of doing this, and make no mistake, these musicians know the original progression.
There are two sides to every sonority
Color in the sonority from a linear/line perspective (like walking up and down a staircase).
Color in the sonority's skeleton or bare bones (like walking up and down a staircase, but skipping every other step).
What are scales? Scales are vehicles used to communicate sonorities. They are collections of notes that are arranged in steps (usually half-steps or whole-steps). Some scales even have a minor-third interval or two (ex: C-Eb or F-Ab) within their arrangement.
Playing a scale that is associated with a given sonority (this takes patience and practice for your brain to internalize) will instantly color or "light-up" that sonority to completion. Scales color in the whole sonority.
This is why improvising musicians learn scales. A particular scale will instantly give you access to a particular sonority.
Bear in mind that people tend to attach different moods and emotions to sonorities. Likewise, scales have these same associations -- some are happy, some are sad, and everything in between is also possible. But this is not an exact science. Other musical variables can also affect the emotions that listeners feel.
"Playing a scale associated with a given sonority will instantly color or "light-up" that sonority."
A sonority's primary scale colors in the sonority with complete detail.
Scales that are not primary to a given sonority can also be used, though they may color in only certain aspects of the sonority or add in passing tones.
The notes in a particular scale (any scale) are called scale tones.
"Each sonority can generally accommodate many different scale options. But there is usually one primary scale that colors in the sonority with complete detail."
What are chords? Chords occur when you stack a sonority's primary scale in diatonic 3rd intervals off of the root. "Diatonic" means “only the notes in a given scale”, in other words, the scale tones.
For example, in the D dorian scale, the notes D, E, F, G, A, B, and C are diatonic. Stacked in 3rd's, this would be: D, F, A, C for a D minor7 chord. These first four stacked thirds are called chord tones.
Continuing the pattern would add the notes E, G, B, and D. These notes would be called upper extensions. The pianist or guitarist may add these notes to add more color to the chord.
"Chords get straight to the heart of the sonority and fill in the sonority's skeleton or bare bones. The primary scale fills in everything -- the skeleton, muscles, and skin."
Pianists and guitarists will tend to voice chords in a historical and/or personalized way, rather than just play them in stacked 3rds. There is a lot of art to this. Check out pianist Peter Martin and his voicings:
"Perhaps most important: the more experience you get with scales and chords through study on your instrument, at the piano, and through playing and listening to music, the less they will seem like letters and numbers. The associations will begin to make musical sense to your ear."
© Zubin Edalji, 2021