I have been trying for at least half a year to find out how people name chords but I never could understand how. Especially when the Internet has people that don't agree. I learnt something about a subject called mathematical music theory that used the chromatic scale to analyse music. Pretty much I was wondering if there is there any different system of naming chords that uses the chromatic scale.
I learnt something about a subject called mathematical music theory that used the chromatic scale to analyse music. Pretty much I was wondering if there is there any different system of naming chords that uses the chromatic scale.
topo morto already answered this in a comment but I will add more information, and a bit of editorializing. My go-to reference for atonal "chord" structure is Allen Forte's "The Structure of Atonal Music" from 1973. He was a professor of music theory at Yale and the book is published by Yale University Press.
Forte's main unit of analysis of a group of notes called a "pitch class set." Naming a given chord involves transposing all the member notes into the same octave and giving them numbers 0-11 which correspond to the half-step relationships, and placing these numbers in a set of square braces. A major chord could be notated or named as [0, 4, 7], but there are translations, transpositions, orderings, and other operations to consider as well, which he goes into.
The analysis tools he present have been shown to provide interesting insights into atonal music, but I think that they can also have some application to tonal music, especially where the line blurs between the two approaches and the intervalic content of motifs have correspondences.
In any event, is mathematical (making extensive use of set theory) and pertains to the entire chromatic scale, as you asked.
As for other theories of naming chords, yes there are many, and there are disagreements. Some of the disagreements arise from considering the music from the vantage point of different traditions. AFAIK, in Jazz for example, the more classical approach of John Mehegan (for example) will have points of differences with, say, George Russell's landmark "Lydian Chromatic Concept of Tonal Organization" which will in turn have points of disagreement with the charts and lead sheets that are being passed back and forth by gigging musicians.
I don't think there is a single system that can unify music analysis. Or if there is, it will be very unwieldy, because there are so many different ways people listen, many of which are not conscious and embedded as part of a particular tradition.
I don't understand the downvotes here. To the unitiated, chords are confusing so I can see how it's difficult to ask this question in a real straightforward way if you're really in the dark about it to begin with.
Let's start with some basics:
A major chord is made up of the 1st, 3trd, and 5th degress of the scale it belongs to. For example, a
C major chord is made up of
C E G. The
C major scale is:
[C] D [E] F [G] A B (I've put the notes from the chords in brackets).
And, like the article shows, these can be inverted; The 1st (or
C) in this case, doesn't need to be the bottom note for it to be called a
C major chord.
Now let's talk about a major seven chord. Using the same scale, we'll just add the 7th degree of the
C major scale, which is
C major 7 (written as
Cmaj7 or other variations) is:
C E G B. Again, you can change the order and the chord is named the same. This is still
G B C E.
When you invert a chord, it is generally done for one of two reasons:
- To give the chord a different quality:
C E Gsounds different than
E G Ceven though the notes are the same. In this case, having the
Eon the bottom puts the harmonics in different relation to one another. In this use case, I would also have the bass play
E. This can be called
C in first inversionor even just
C/E— which is spoken as "C over E" or "C major over E.
- I may write in, say, a piano part that I want a
C majorchord played as
E G C(we would call this a "voicing"), but still have the bass play
C. Why would I do this? For a variety of reasons. Maybe there's a vocalist singing the lower C and I don't want to double it or maybe I just like the sound of this voicing.
Taking it further
If you just take the major scale as a starting point, you end up with seven scales, one based off of each degree of the
C major scale:
C D E F G A B:
C major link
D E F G A B C:
D dorian link
E F G A B C D:
E phrygian link
F G A B C D E:
F lydian link
G A B C D E D:
G mixolydian (what a dominant chord is based off of) link
A B C D E F G:
A aeolian link
B C D E F G A:
B locrian link
As for the chord names, if you take each of these scales, with their sevent degree, then the names are:
C E G B:
C major 7
D F A C:
D minor 7
E G B D:
E minor 7
F A C E:
F major 7
G B D F:
G dominant 7
A C E G:
A minor 7
B D F A:
B minor 7, flat 5 (You may hear some people call this
B half-diminished. It means the exact same thing.)
Now, remember that thing I mentioned about being able to invert the notes in a chord? Check this out:
C E G A
This can be thought of as
C6 (it's the
C major chord plus the sixth degree of the
C major scale OR it can be
A minor 7 in first inversion (I could write it as
Am7/C (spoken as "A minor 7 over C"). They're the same notes, but called two different names because of context. Though it's largely subjective, musically, it might not make much "sense" to write
C6 if what came before or will come after the chord doesn't give the
C6 the proper context. Here's an example, based off a very common progression,
1 6 2 5 or
I vi ii V if you want to use roman numerals:
C Am7 Dm G7
I could have written this:
C C6/A Dm G7, but the
C6/A doesn't make much sense in terms of the musical context. Sure they're the same notes, but the idea is that I'm moving from the first degree of the scale (
C) to the sixth (
A), to the second (
D) to the fifth (
Finally, you mentioned people not being able to agree on the names of chords. This is largely because depending on someone's training and the context in which they're talking about the chords, they may actually be named differently. Also, some people might just be misinformed. For example, if you ever called
C E G "C minor" you'd just be incorrect. However, if you called
C E G A "C six" or "A minor 7 over C", both could be "correct".
Remember, a lot of music is subjective, even when it comes to music theory. Let your ear guide you, don't be afraid to be wrong, and ask musicians you respect for advice and why they chose the chord they chose, regardless of the name.