Microtonality and Jazz

There are many places to find evidence of microtonality in jazz. A good place to start is a transcription of Robert Johnson's microtonal singing at Tonalsoft, Joe Monzo's site. Louie Armstrong is another player that naturally made use of a broader, more expressive and precise pallette of tones. It makes since that improvising musicians, working from their ear and experience, put to use what would be the logical extension of the Western tonal system. Alot of electric blues players like Jimi Hendrix and Buddy Guy obviously get alot microtonal stuff going on. Have you ever known a good blues player that didn't bend all over the place? It is funny that when current musical theory cannot explain what 'folk' musicians play, it becomes a real wishy-washy, 'unexplainable something' that is, nonetheless, demanded. Bill Frisell, on a track on 'Blues Dream', plays very distictly the two blue thirds(being a 1/6 tone under and a 1/6 tone above the ET minor third).
Then you have saxophonists like Coltrane and Ornette Coleman, who played very intsinctively, intonation wise. This is all very much related to the artistic interpretation of a melody or solo, meaning the players are mostly playing the microtonal intervals intuitively in performance. Another aspect to consider is the actual harmonic progression of jazz within 12-tone ET, and the ways the sytem points beyond itself.
First let's look at blues harmony. In blues, what we think of as a dominant 7th chord is tonicized. So the tonic chord of the tune has a major third and flat seventh - a chord which would demand resolution in Western harmony. But in this case, we are talking about a naturally extended 7th chord derived from the overtone series where the 7th harmonic is in fact a flat seventh, 30 cents lower than the ET interval. So already the harmony of blues demands an interval that cannot be supplied by the piano. This is where the lower of the two blue thirds comes from. The interval 7:6 from the fundamental. (In C it would be the interval from G to 1/6 low Bb, moved down to the lower pentachord:C to 1/6 low Eb). This is called the septimal(7) minor third and represents the first step beyond what the piano can give us.
But many piano players have also made significant contributions to the move toward microtonality. Take for example, Bill Evans. He introduced a way of playing cluster voicings that could treat an entire diatonic scale as consonant harmonic material. This has two things working for it. 1)It simply continues the tradition of extending what is thought of as consonant within the diatonic scale by creating structures that adequately support in our new ears an extended amount of 'resting tones'. 2)Based on the phenomenon of resultant tones(as Sims calls it; I see it also as taking a harmonic mean) when the interval of a minor second is played, it implies a third note in between the two played and an octave up. So by playing cluster voicings, especially with minor seconds, Evans created a microtonal atmosphere 'above' the notes he actually played on the piano. Monk was also known for this same technique.
This is all just to show how surrounded we are by this development and how natural the transition will be. We cannot, however, continue to incessantly imply these advanced harmonies without actually modifying our system. That is what is such a pain in the ass about alot of jazz players; they feel like they are being courageous and on the forefront of harmonic development and bitch about the low level of their audience's ears, when they are really just spewing alot of very unnatural, contrived crap. There becomes a very large disconnect between what we hear and what our cognitive process knows we should be hearing, and as these drift further and further away from each other, the experience of listening becomes more and more an intellectual one(piecing together the puzzle) rather than a wholistic, resonant, energetic, spiritual, bodily one.

I've been working on writing three part harmony with the 18-24 tone scale of Sims that I record with my fretless one part at a time. I also will be getting my 36 tone guitar in just a few days. I believe a full fledged microtonal project with keyboardist Matt Weires will be getting under way.