Enough of the easy stuff, back to work! In this post, and maybe
the next, I’d like to talk about harmonic categories. This is a
concept I learned at Berklee, and it has helped me quite a bit
over the years. First I’d like to give a little background info on
A key consists of a 7 note scale and 7 chords built from that
scale. There are 12 keys, one starting from each note in the
chromatic scale, and each is different. (If you have no idea
what I’m talking about, either skip this post or get a copy of
my book, “Take Control: for guitar” available on Amazon).
I will be using the key of C in this post, to make it easier.
The key of C major consists of a C major scale ( notes; c, d,
e, f, g, a, b, etc.) and the chords built off of those notes;
C major, D minor, E minor, F major, G major, A minor, and
B diminished. For a musician, the practical meaning of this
is you can combine and play any sequence of chords from
this group and solo/sing the scale notes over it (again in any
sequence) and it will always work. Understanding how
chords and scales fit together in a key is helpful in jamming,
composing, and transcription. Enough about keys, now let’s
talk about harmonic categories.
In any key, the 7 chords contained will fall into 3 harmonic
categories; Tonic, Subdominant, and Dominant. The chords
in each of these categories sound similar to one another, and
occupy the same harmonic space (or function) in the key.
Before I explore this concept further, I will list the chords in
each of the 3 categories, both by chord name in the key of C,
and by scale degree* so you can use this concept for any key.
TONIC: contains the root chord, C major (I), E minor (iii),
and A minor (vi).
SUBDOMINANT: contains the F major chord (IV), and D
DOMINANT: contains the G major chord (V), and the B
diminished chord (viiº).
*I hate to sound like a recording, but if you don’t understand
scale degrees ( those Roman numbers), get a copy of my
book, “Take Control: for guitar” and learn it! It’s quite handy.
The first practical use for this information is chord
substitution. Jazz players do this all the time! If a song is in
the key of C and you’re playing a C chord, try an A minor
instead. Or try an E minor, any chord in the Tonic category
for the key of C. You may like some choices better than
others, but they will all substitute for one another. This
works the same for the other 2 categories. In the Dominant
category, try substituting a Bº for a G7. It may be the only
time you can actually use a diminished chord!
Before I explore other uses, I will have to explain the
concept of harmonic function, which I mentioned earlier.
I will do that in my next post, see you then.