The idea of chord type is what I’d call a devious concept. It’s devious because it appears so close to the concept I actually want that it makes me assume it is what I want. As a musician, what I want is a way of understanding and categorizing the different sounds (or sound experiences) I can create by playing groups of notes in a connected way. I want a way of thinking about compound sounds. What does the notion of “chord type” actually do? It helps us identify the intervallic structures that arise when we combine notes in certain ways–it’s a technical, essentially mathematical notion that relates to sound but doesn’t describe sound.
For example, a major triad in root position is a major third with a minor third stacked on top it: four semitones plus three semitones. And the major chord type extends to any transposition or inversion of that interval structure. We get so used to thinking in terms of chord type that we equate it with sound: a major chord has a major sound; if you want a major sound you should use a major chord. To analyze a piece of music often means “figure out what chords (i.e. interval structures) are being played and how they relate to each other functionally,” and once we’ve done that, we think we understand what’s going on. And yet it’s easy to forget that interval structure is not the be-all end-all of sound experience — in fact, it’s far from a natural way of conceptualizing sound experience. As a student, you don’t always know what concept you want so you take what’s there and forget there’s something missing.
Now the holy grail of sound classification is probably unattainable, not only because sound experience is subjective, but because it is influenced by so many factors including context (musical, psychological, and cultural), register, articulation, tuning, and so on. So we’re left with this idea of interval structures and the names we’ve given them — major seventh, minor seventh flat five, Lydian dominant, etc. We go on assuming that (harmonic) music is made of chords and chords are made of interval relationships, and anything you want to know is contained therein.
This post is a “rant” — I needed to get it off my mind because I’m about to publish some material on chord types. And yes, I realize that most musicians know there’s a lot more to sound than interval structure. My real reason for writing this post is to stamp out a reductionist bias that I find myself falling into from time to time.