(Original posted on October 22, 1999)
Numerous questions regarding the music called “Blues” would converge as questions about “Blue Notes.” Various musicians and musicologists have attempted to clarify them in different ways. However, when pursued theoretically, their charm as music quickly fades, often resulting in mere observations, failing to fully grasp the music of the blues. Ultimately, one could only passively immerse themselves in the music.
Amidst this, “Blue Notes and Tonality” took a new perspective, addressing the problem that “understanding blue notes cannot be achieved through repeated static observation, and moreover, the issue lies in the sense of tonal薄弱ness and the bitonal, polytonal nature inherent in the blues scale that modalized blue notes – where do they come from? For this reason, a dynamic grasp against the background of harmonic progression is necessary.”
This book can be said to provide the reader with a very unique musical image. The author, Motohiko Hamase, states, “I was able to show a completely new tonal structure,” and I will briefly explore what that entails.
The book begins by logically demonstrating the basis for the occurrence of blue notes, based on the problem of “perfect fifth ascending progressions difficult to treat as strong progressions (essentially, progression from IV to I)” appearing in blues and the idea of the “descending harmonic series.” Taking this as a foothold, it sets the “descending harmonic series region” as a collection of major and minor triads generated from the descending and ascending harmonic series. And it asserts that the value of this region lies not in “root progression” as shown by conventional tonality theory, but in “modality and harmonic color.” In other words, it considers the multitude of scales that can arise within this descending harmonic series region as a “set sum,” seeking musical value in the “richness of sound” such as the coexistence of multiple scales within the set, scale transformations, or transitions to other sets. It is likely for these reasons that this region is called a “region equipped with bitonality and polymodality.”
What is interesting is the point that the blues scale, which became the basis for the emergence of this region, is consistently able to coexist and endure within the same region. That is to say, in a sustained sound space where a certain blues scale (or phrase, etc.) resonates, all musical material from the descending harmonic series region generated from that blues scale can coexist.
Conversely, if the author has a clear tonic (tonal center) in mind, it is not necessarily required to express it audibly. A style of building sounds while recognizing a sustained sound space as a descending harmonic series region is also possible. And the subtle sense of tonality that arises at this time should overlap with the characteristics of this region.
Subsequently, the author presents a method centered on “scale exchange mediated by chords” as a direction for obtaining “richness of sound.” Starting with an examination of the relationship between chords and scales, this is replaced with upper structure triads, leading to a collection of hybrid chords. Note that the process of scale exchange mediated by these hybrid chords is demonstrated in later chapters.
Now, this is where the book shows its power. Here, it focuses on the “sus4 chord,” a chord that avoids clarifying tonality, or in other words, avoids dominant motion. From the perspective of classical harmony, it is merely a suspension, but in the world of jazz, it has long been noted as a foothold for new sounds that seem to “float away from tonality.”
The author hybridizes the sus4 chord and identifies scales that have this chord as their set intersection. The polymodality (set of scales) confirmed in this way is, astonishingly, completely identical to the polymodality that appears in the descending harmonic series region. This discovery will likely change the perspective on existing chords and musical viewpoints. And not only that, but it may allow us to hear a different sound order (sound world) that is not bound by root progression.
It seems that this “different sound order unbound by root progression” and the traditional “world of strong progression based on the ascending harmonic series” are referred to as the “new tonal structure,” representing a relationship of yin and yang. By viewing harmonic progression and melodic flow through the lens of the descending harmonic series region, a completely different angle of musical understanding will arise. It is truly an expansion of musical perspective.
As described above, this book is an excellent “practical” theoretical book. However, some readers may not be convinced by the descending harmonic series premise, which is fundamental to the 논지. As the author himself says, it is “mathematically speaking, a world of imaginary numbers.” In music, which is not solely a world of logic, this point becomes problematic. Perhaps to reinforce this point, the author uses the theory of the music acoustician Helmholtz, specifically “combination tones,” to show that the occurrence of bVII and bIII from the descending harmonic series and their root formation (becoming the root of a triad) can be confirmed even in the “real world.”
Lastly, this book comes with a CD, so the “exchange and development” discussed in the latter half can all be confirmed by ear.
※2025年追記。その後、下方倍音が知覚される状況や個人差について論文が発表されています。
Link 『下方倍音知覚の動力学』本條晴一郎
