Who else wants to know the relationship between the tertian harmony and the 2-5-1 chord progression.
The 2-5-1 chord progression is the strongest chord progression in tonal music and is commonly used in jazz and gospel music.
Submission: If you’re classically trained, you’ll also appreciate the 2-5-1 chord progression as well because of its use especially at cadential points.
Today, I’m going to show you why the 2-5-1 chord progression is favored by the tertian harmony. But before I do so, permit me to refresh your mind on the concept of tertian harmony.
A Short Note On The Tertian Harmony
The notes of a chord are related by class of harmony; which is concerned with the distance between the successive tones of a chord when played in root position.
The C major triad consists of C, E, and G:
…which are related by a class of harmony known as the tertian harmony.
The Tertian Harmony — Defined
Using any given scale as a reference, tertian harmony is produced by a collection of tones (referred to as a chord) where the distance between successive chord tones is a third interval.
The C major triad:
…is a product of the tertian harmony and this is because of the fixed third intervals between successive tones:
C to E:
…is a third interval.E to G:
…is a third interval.
Every other triad in the key of C major:
D minor triad:
E minor triad:
F major triad:
G major triad:
A minor triad:
B diminished triad:
…is also a product of the tertian harmony and this is because of the third interval between successive tones.
Here Are All The Tones In The Tertian Harmony (From C to C)
Starting from C:
…and adding tones in third intervals (tertian harmony) until the next C is reached:
C:
…to E:
…to G:
…to B:
…to D:
…to F:
…to A:
…to C:
…produces all the tones in the tertian harmony (“C E G B D F A C”):
…using the C major scale (as a reference):
“Here’s A Quick Mnemonic To Memorize The Tertian Harmony With…”
Using the mnemonic below:
C-Every-Good-Boy-Deserves-Favor-Always-C
…you can memorize the tones of the tertian harmony.
“Check It Out…”
C:
Every:
Good:
Boy:
Deserves:
Favor:
Always:
C:
C-Every-Good-Boy-Deserves-Favor-Always-C:
Why The Tertian Harmony Favors The 2-5-1 Chord Progression
The 2-5-1 chord progression consists of the movement of the following chords:
The 2-chord
The 5-chord
The 1-chord
…in any given major key.
In this segment, I’ll be taking you by the hand and showing you why the tertian harmony favors the 2-5-1 chord progression and I’ll be using triad and seventh chord examples.
Attention: Kindly note that all the examples will be given in the key of C major.
The 2-5-1 Chord Progression Using Triads
In the key of C major:
…where the second tone of the scale is D:
…the 2-chord is the D minor triad:
…consisting of D, F, and A.
The 5-chord is the G major triad:
…and it consists of G, B, and D.
Then the 1-chord consists of C, E, and G:
…which is the C major triad.
“Check Out The Chords For The 2-5-1 Chord Progression…”
Using “C E G B D F A C” (as a reference), you can find the 2-5-1 chord progression in the tertian harmony:
2-chord = C E G B [D F A] C
5-chord = C E [G B D] F A C
1-chord = [C E G] B D F A C
The 2-5-1 Chord Progression Using Seventh Chords
The 2-5-1 chord progression can also be played with seventh chord:
The D minor seventh chord (the 2-chord):
The G dominant seventh chord (the 5-chord):
The C major seventh chord (the 1-chord):
…and these chords are favored by the tertian harmony.
Using “C E G B D F A C” (as a reference), you can find the 2-5-1 chord progression in the tertian harmony:
2-chord = C E G B [D F A C]
5-chord = C E [G B D F] A C
1-chord = [C E G B] D F A C
That, ladies and gentlemen, is the relationship between the 2-5-1 chord progression and the tertian harmony — not just in the key of C major, but in all major keys.
Final Words
The relationship between tertian harmony and the 2-5-1 chord progression cannot be overlooked.
Thank you for your time and see you in another lesson.
