Lesson 4: chords

Today we shall precisely define a major key.

We shall use the key of C as an example,
which we shall use in all of our examples because it does not have # sharps or flats in its key

It is, however, fundamental to always remember that all the other 11 major scales
share the same definitions we are about to give to the one in C.

We will now build a chord using the 7 notes of the major scale.
Chords are built by adding the third, fifth and often seventh tones to the base note.
This means they are built by superimposing thirds:
first the base note, then its 3rd and 5th tones, and the seventh when making a chords of the ninth.

We use this process in order to build a chord on every note of the major scale of C.
In adding the thirds we shall use only the notes included in the major scale of C
(therefore there will not be # sharps nor flats).

These are the chords that can be extracted from the major C scale.
A chord is made of at least three notes (or voices).

Two simultaneous notes do not determine a chord, but a bichord,
that is identified by the type of interval it proposes.

By chords we mean at least 3 sounds obtained by adding at least 2 more tones to the first one
that gives the name to the chord at a distance of a third from each other.
Chords are therefore formed by the first note, called the root, to which are added its 3rd and 5th tones.

As we learn how to correctly use these triads through follow-up lessons and progress in the study,
we shall also see chords with the 7th and 9th tones.
For now, we shall limit ourselves to defining chords formed by the root, with its third and its fifth tone.

These 3 tones also define the complete name of the chord:
The low tone to which are added the other two tones at an interval of a third
is called the tonic or root of the chord and will be the beginning of its name.

If the interval of a third from the root is major, the chord shall be major.
C, F or G are the major chords in the tone of C.
By convention, when the third is major we do not need to name the chord;
it is certain that C, F, G means C major, F major, G major.

If the interval of a third from the root is minor, the chord shall also be minor,
and this time it is necessary to indicate it in its name.
Dm, Em, Am, Bmb5 are the minor chords present within the C major tone.

The fifth interval from the root is not mentioned in the name if the 5 is major.
According to the established measuring intervals,
the 5th interval might be major, diminished or augmented.
When the 5 is major it will not be necessary to specify it in the name.
When the 5 is augmented (#5) or diminished (b5), the name of the chord will have to specify that.

The name of these chords
C, Cm, Cm5b

The latter is found in the case of the chord built on VII,
the B that we find in the tonality of C (B-D-F).

This chord is called Bmb5 (or Bm5b, easier to read).
It is a dissonant chord, very unstable and is often used with the necessary adaptation
in order to respect its tendency within harmonic coherent schemes,
which we shall discuss in depth shortly.

On the basis of what we have established so far we can also state that a major tonality C is composed of:

3 major chords (C,F,G)
3 minor chords (Dm, Em, Am)
1 minor chord with diminished 5 (Bm5b).

We can therefore update our table of the 12 scales which will not only specify just which are the notes composing major scales, but which shall define chords built on the diverse grades of our 12 major tonalities.

In this new graphic representation we can see that a major chord
(C, in this case, highlighted in yellow) can be in the 1st, 4th or 5th position of a major scale.

That means that C major is first in the tone of C, fourth in the tone of G, fifth in the tone of F.

Analogous interpretation can be given for the minor chord II Am,
highlighted in pink which can be interpreted as a VI of C, II of G and III of F.

The sounds composing the major scale are called grades of the scale
and are numbered in Roman numerals.

The major scale contains 3 major chords (over grades I, IV, V), and three minor chords (over II, III, VI).
This naturally implies that a major or minor chord can be part of 3 different major /tonalities.

Every grade then has a specific name that tries to describe its position and harmonic role.

When we are in the tone of C, A will be its VI grade, its superdominant.
If we refer to the chord on the IV grade of C tonality or its underdominant, that corresponds to the F chord (major).

And this is obviously the case for all 12 major tonalities.

At this point knowing the chords of all tonalities (Majors) one could feel ready to exercise one's pen
in a fantastic symphony flying amidst all these chords we have mentioned,
perhaps between all tonalities, free as a butterfly.

But before that, a few more clarifications will be necessary:
you will have to be patient for a few more lessons; soon it will be time for practice.