Jazz Harmony

Brief history of harmony
from origins to Jazz

by Martin Antaya

A simple definition of harmony is: the study of chords and their progressions, a chord being made of multiple notes being heard simultaneously. For harmony to be, there needs to be polyphony: many voices (melodic lines) playing at the same time, by opposition to monody, a single voice for all instruments.

I-Origins

Historically, music was first monophonic. In the twelfth century, Léonin and Pérotin composed organums, pieces where one voice would stay fixed while the other would move, creating different intervals. Then monophonic gregorian chants of the middle-ages were used as Cantus Firmus (first chant) to form polyphonic pieces. Forms that will later give birth to the fugue (where a melody is successively heard in different voices, in an imitation style) abound. Music is mostly vocal.

With the rise of instrumental music, the tonal system appears around the sixteenth century: a scale is used prioritizing a note, the tonic, as a harmony's central point. The other notes are assigned a special relationship with that tonic and some chord progressions become standard. The different steps of the scale acquire a function, of which the most important are the dominant (V) and the sub-dominant (IV). Harmonic rhythms succeeding chords separated by a distance of a perfect fifth make their appearance.

In the seventeenth century (baroque), chords are starting to be notated by a numbering system over a bass line, called figured bass (or continuo style). Chords usually contain 3 notes, except the dominants that may have 4. In that case, other steps need to prepare and resolve the 4th note properly. Altered chords are also of fashion in the baroque era. Some genius composers like J-S Bach preserve the art of counterpoint and heterophonic music (many melodies running simultaneously)...

... but homophonic music (an accompanied melody), literally takes over in the eighteenth century, starting with Haydn, Mozart and the like. Later on, Beethoven, a master of dramatic effects and counterpoint features, also uses the 5-note chords like the dominant seventh with a  minor ninth (V7b9) as a dramatic effect.

The romantic period of the nineteenth century sees the appearance of modulations to unrelated (and remote!) keys in the tonal system. It stretches to a maximum with such works as Wagner's "Tristan and Isolde" with ultra-chromaticism, where chord progressions are made by half-step voice leading. 

Like a rubber band, after being stretched, the tonal system later breaks. Thanks to German composers such as Schoenberg and their atonal music, where there is no tonic, nor scale. 

Different systems are used thereafter: serialism (a succession of notes in a numbered suite) and dodecaphonism (twelve-tone row, made of each of the 12 notes) that finally led to integral serialism: every musical parameter (pitch, rhythms, dynamics, etc.) controlled by a numbered suite, the different series being played in order, each one repeating its cycle and crossing-over until the end. Composers such as Webern used this system exclusively.

In the twentieth century, the modal system comes back to life with composer such as Debussy and Ravel: exotic scales are used whilst applying the occidental harmony system. The modal system is more flexible and less stereotyped as compared to the "strict" tonal system: we hear very few V-I cadence; moreover, modes/scales can contain more or less than 7 notes. Another experiment was made by Darius Milhaud who superposed two different tonalities, thus creating polytonality.

II-Jazz

Early twentieth century composers (mainly American ones) like George Gershwin were influenced by jazz. This "new music" was born at the time, findings its root in the Afro-American music tradition, such as gospel, blues and ragtime. These different "styles" of music emphasize the strong degrees of the tonal system as bass notes : (I, IV and V). Some more obvious characteristics :

• Gospel makes use of the plagal (IV-I) cadence a lot;
  
  
• Blues colorizes those degrees with a dominant 7th sound, adding the blue note (#9 alias "sharp nine");
  
  
• While Ragtime, with the illustrious Scott Joplin as a main figure, offers a outrageously syncopated rhythm, putting accents on the weak beats of the bar.

After the First World War, jazz songs bloomed, many of which still constitute the core of the standard jazz repertoire today. The fast and swinging times of big bands like Duke Ellington's in the 1930s dint' last though : they eventually disappear during World War II for small ensembles, budget obliges. 

Bebop was born then, featuring Charlie Parker, Miles Davis and Dizzy Gillespie. Besides fast tempos, bebop makes an abundant use of 9th, 11th and 13th in the chords. 

In those years, Gillespie will go on working with Cuban musicians developing Cuban rhythms into afro-cuban music, whilst Davis will "switch" to cool jazz (where a small ensemble imitates the diversity of harmonization of a bigger ensemble.) Miles Davis, was trained in bebop but didn't stay in it for too long. He was real pioneer and a leading figure in jazz of the 50's, 60's and 70's. He did :

• collaborate with Gil Evans and its refined instrumentation of unusual combination of instruments (cool jazz);

• re-create the small ensemble sound playing jazz and pop songs of the era (first great quintet);

• initiate the modal jazz movement in the late 50s, spurting the 1959 "Kind of Blue" album, (where less chords is better);
  

• re-re-create the small ensembles sound in the 60s, playing original jazz compositions with Wayne Shorter, Herbie Hancock, Tony Williams and Ron Carter (second great quintet);

• introduce so-called "fusion" to the general public in the late 60s, using electric instruments on "In a silent way", improvising in different modes simultaneously on "Bitches Brew", 

• (finally) create fully improvised music over a bass groove (70s), with a trumpet sound tinted with wah-wah pedal, (very atonal).

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John Coltrane, who started his career with first great Miles Davis quintet, will explore cyclical modulations, like in "Giant steps" (1959) where II-V-I progressions in relation of a major 3rd, but will then experiment chordless music, long and cloudy melodic spurs, like a tapestry of sound. He even ventured to remove pulsation on certain pieces.

The jazz-fusion movement in the 70's will also see John McLaughlin (who also started out with Miles...) and his Mahavishnu Orchestra use exotic modes and odd meters, giving birth to contemporary harmony, sometimes symmetrical (motives repeating at mathematical intervals) and breed with Indian music with Shakti, making sitar sounds with his acoustic guitar and using Indian modes and motives.

The 80s will favor more radio-friendly pop sounds, with Jaco Pastorius and Weather Report, George Benson, and notably the Quebecer group Uzeb. A simple yet refined pop harmony prevails. Since the 90s, many "styles" of Jazz share the stage, from the most mainstream to the more eclectic, with frequent interbreeding with popular music. The majority of today's Jazz, though, stays related to the tonal system.

III-Conclusion...

To synthesize, we observe in traditional jazz harmony the use of 4-note chords (mainly, often more) as opposed to 3-note chords in classical. We can also notice the abolition of classical voice leading rules (avoidance of consecutive parallel 5th or 8ve, leading tone goes to tonic, etc.) 

Jazz harmony still uses some voice leading principles, but the musician who accompanies with chords (comping) will mostly apply the concept to the "top voice" of the voicings, without necessarily seeking independent and autonomous voices (which were the reason of classical rules in the first place.)

Also, chords having more density need no more to resolve their non-chordal tones. In jazz 7ths, 9ths, 11ths and 13ths can now be part of an actual chord. 

Finally, it is clear that the II-V-I cadence is preferred in jazz to IV-V-I of the classical harmony, but progressions in cycle of 5th remained quite common in jazz harmony. 

Let's bet that Jazz, who is only 100
years old, has not spoken its last word...

February 17th, 2011