Hey Jazz Guy,
I want to play outside, but I’m just stabbing in the dark and everything I play sounds wrong. Where do I begin? –Wrong in Wichita
This is a common issue when learning to hear and play complex harmony. To truly understand outside playing and upper structure harmony, we must ask where it comes from, and why it works. There is a natural, physical reason for why notes sound inside or outside. When you strike a string that is fixed on both ends, like a guitar string, it vibrates at a fundamental frequency such as E. The string also vibrates at other frequencies in proportion to the fundamental called harmonics. The way these harmonics, or overtones, appear inside the original note is called the Overtone Series [Ex 1]. Notice that these frequencies can be transposed into the same octave and the result resembles a western chromatic scale [Ex 2]. The problem with this is that some of the higher harmonics are out of tune with our 12 tone system, meaning that if we played music based on natural harmonics, only certain notes would be in tune in each key. The solution to this problem was to “round off” the frequencies and divide the octave into 12 equal parts. This is called “12 tone equal temperament“. During the late Middle Ages and Baroque era, the equal tempered tuning became the dominant tuning system, because it allowed for complete freedom of modulation and expressiveness in all keys. If the equal tempered system had never become commonplace, then music with a high degree of harmonic activity like jazz, would not have been possible. The overtone series is a book unto itself, and this is the principle behind why you can play outside. The chord tones and melodic tensions are already there in every note you play! Justa lot higher than the original note. Thus, one great way to approach harmony in general is to keep register in mind and play vertically. To apply this, take an F major triad [Ex 3] and then go up in thirds three more notes, so we have FMaj7(9#11) (Play this by tapping with both hands). If we play a line with only these notes, it feels very inside over FMaj7. Moving up the diatonic scale we get great tensions on each chord such as Gmin7(9,11) and Dmin7(9,11) [Ex 5]. (Note, can only be by played by tapping in these inversions [Ex 6]). Notice the F natural on C7. Usually, theory says that the 4th is the “avoid” note in a mixolydian scale but when you play it vertically [Ex 6]it sounds inside. This demonstrates the power of playing vertically. Everything can sound “inside” when placed in the correct register. This idea alone can take your harmonic concept to a new level. It applies to chords of any type, playing vertically on the altered chord in [Ex 7] leads to a Gb triad over the C7. If we try this concept on a I-vi-ii-V progression [Ex 8], we get lines that use many of the diatonic and altered tensions. Finally, ratchet up a notch and play an “out” vertical line [Ex 9] over FMaj7. We are playing b9 on a Maj7 chord! By continuing to stack thirds, notes that would never appear in the chord scale, appear in the upper structure. Playing those notes works because playing vertically leads your ear to notes that are already there in the overtones. This is a complex concept that can be used as a guide to find great outside ideas and train your ears to hear the intricacies and possibilities of upper structure harmony. There are many ways to play outside the box, so remember where it all comes from every time you strike those strings. Jazz Hard!