3) From our chord definition we now come to that phrase
A chord is an aggregate of three or more related notes, which may be agreeable or not, which may be played or heard together.
The notes of a chord can be either pleasant or unpleasant when played. I am using these terms relatively.
For unpleasant, I mean in the sense of harsh, or unstable. Discordant chords carry the feeling that they need to be resolved somehow.
A pleasant combination of notes are said to be concordant.
Whereas an unpleasant combination of notes are said to be discordant.
We have all played a discord at some time or other!
So a chord may be either a concord or a discord and this depends on the intervals between the notes in that chord.
We all know that chords, which are made up of, a perfect fifth, and/or major and minor third intervals, are concordant.
Whereas chords that are made up of augmented and diminished intervals are particularly discordant.
This does not make them wrong, or even inferior in any way.
The term is used to describe those chords, and recognises that they have a different function or purpose.
So going back to our example of the C major triad, this is a demonstration of a concord.
Why is this so?
Well, to breakdown that C major triad, which consists of the notes:
C E G
into its intervals, gives us:
C to E
which is a major third interval.
And
E to G
which is a minor third interval.
Also notice that the notes:
C to G
is a perfect fifth interval.
So, the reason why the C major triad sounds pleasant, when we play it, is because of those intervals it is made up of.
They are, as we have seen, the major third, the minor third, and the perfect fifth.
In the next Reply, we will consider the discordant chords.
Peter