You might probably have the playing the Guitar for years but if you lack this basic foundation about chord formation then you have a lot of work to do.
What is a THIRD?
A Third is an interval of 3 notes.
A-B-C A to C is a third.
G-A-B G to B is a third.
NOTE: it does not matter if it’s a tone or semitone interval.
There are two types of thirds. Major and minor third.
Major third:This is the combination of two tone ahead of the root.
E.g; C-E, A-C#, F-A.
Minor third: This is the combination of a tone and half distance from the root.
E.g C-D#, E-G, D-F.
The great question now should be HOW DOES THIRD LEADS TO THE FORMATION OF CHORDS?
Chords are formed by the stacking of thirds together.
What then is a CHORD?
A chord is the combination of more than two notes played together.
There are many types of chords, but there are four types of chords that I will call the foundational chords.
From these four chords, every other chords are derived and generated from except for some hybrid types of chords.
These four chords are Major chord, Minor chord, Augmented chord and Diminished chord
MAJOR CHORD
These are formed by the stacking of Major third + Minor third together.
C-E + E-G.
C-E is a Major third, E-G is a minor third. The combination of these gives us C-E-G I.e C-E-G is a C Major chord.
F-A is a Major third, A-C is a minor third. F-A-C is an F major of chord
The same process applies to every other notes.
NOTE: the last note of the first third will be the starting note of the added third.
MINOR CHORD
This is the stacking of Minor third + Major third.
D-F is a minor third, F-A is a Major third.
D-F-A is a D minor chord
F-G# is a minor third, G#-C is a Major third.
F-G#-C is a F major chord
The same process also applies to the other notes.
AUGMENTED CHORD
These are formed by the stacking of Major third + Major third
C-E is a Major third, E-G# is a Major third. C-E-G# is a C augmented chord.
F-A is a Major third, A-C# is a Major third.
F-A-C# is F augmented chord
DIMINISHED CHORD
This is the stacking of minor third + minor third.
C-Eb is a minor third, Eb to F# is is a minor third.
C-Eb-F# is a C diminished chord
F-Ab is a minor third, Ab-B is a minor third.
F-Ab-B is an F diminished chord
I hope and believe that this article is analytical as well as an eye opener to all musicians especially musicians that started playing and performing with low or no solid musical foundation. feel free to drop your questions.