Introduction to Triads & Chord Inversions

Description

What is a triad, and what is an inversion? In this tutorial we will explore and learn to play basic triad chord shapes and their inversions in multiple fretboard locations. We will learn how chords are built from scales and the concept of triadic harmony or tertiary harmony.

If we start by remembering that chords are built from scales. Any given chord in it's most fundamental, basic unit is only three notes: the 1st (root), 3rd and 5th from it's respective scale. Therefore, a C major chord is the the 1st (root), 3rd and 5th from a C major scale.

C major scale:

C (1) - D (2) - E (3) - F (4) - G (5) - A (6) - B (7)

C major chord:

C (1) - E (3) - G (5)

So, why do we use the 1st, 3rd, and 5th?

The principle we use to arrive this choice is known as Triadic Harmony; also called Tertiary Harmony. This is because the words triadic and tertiary refer to the number three. Chords are build from scales by means of stacking scale notes that are a third apart.

Informally, I call this the "Leapfrog Principle" because we start by playing the 1st scale note, then leap over the 2nd, then play the 3rd, then leap over of the 4th, then play the 5th. So we are combining the interval of a third, found between the 1st and 3rd scale degree, with the next interval of a third, found between the 3rd and 5th scale degree. We are "stacking thirds" from the scale, playing them at the same time, and this is the origin of the chord.

The result of this is that anywhere, on any musical instrument, you can isolate, find and play these three notes (C, E and G) you are playing a C major chord.

Likewise, if we want to play a D major chord, we start with the D major scale, isolate the 1st, major 3rd and 5th scale notes (or degrees), play them together (or regard them as a unit), and the result is a D major chord.

D major scale:

D (1) - E (2) - F# (3) - G (4) - A (5) - B (6) - C# (7)

D major chord:

D (1) - F# (3) - A (5)

Any given chord is defined by the 1st, 3rd and 5th note of it's respective scale.