Understand major, minor, diminished, and augmented triads as combinations of two thirds, and find them anywhere on the fretboard.
Listen to this lesson
Synthesized voice, not a studio recording
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What you will learn
- The four basic triad qualities and the thirds that build them.
- How root, third, and fifth work together to create a chord identity.
- Triad inversions on the top three strings.
- Why every open guitar chord is just a triad with a few doubled notes.
The concept
A triad is three notes stacked in thirds: a root, a third, and a fifth. Change the size of either third and you change the quality of the triad. Major has a major third on the bottom and a minor third on top. Minor flips that order. Diminished stacks two minor thirds. Augmented stacks two major thirds.
The root names the chord. The third decides if it sounds happy or sad. The fifth gives the chord its weight and locks it to a key. Together they form the smallest unit of Western harmony.
Move the same three notes into different vertical orders and you get inversions. Root position has the root on the bottom, first inversion has the third on the bottom, second inversion has the fifth on the bottom. The chord identity does not change, but the bass line and the colour can change a lot.
On the guitar
Try a C major triad on the top three strings: C on the second string fret one, E on the first string open, G on the third string open. Three notes, three thirds, one chord. Slide that shape up two frets and you get D major (different root, same quality).
Most open guitar chords like E minor or G major contain doubled notes. The E minor open chord plays E twice and B twice and one G in the middle. It is still a three note chord at heart.
Exercises
- 01
Play every triad in C major starting from each scale degree, using only the top three strings.
- 02
Build a D minor triad in root position, then play first and second inversions of the same chord without losing the bass note in between.
- 03
Take a song you know and identify the triad behind each chord, ignoring colour notes.
- 04
Play one triad shape through twelve keys by sliding it up the neck.
Common mistakes
- Skipping the diminished triad because it sounds odd alone. It is essential the moment you reach the seventh chord of any major key.
- Confusing inversions with new chords. C in first inversion is still a C chord, not E something.
- Memorising five basic open chord shapes and never asking which notes are inside them.
Listen, play, create
- Listen: the bridge of Yesterday is rich in triad inversions creating a smooth descending bass.
- Play: cycle through major, minor, diminished, and augmented triads on the same root and notice the emotional shift.
- Create: write a four bar progression using only triads on the top three strings.
Use these tools
Further reading
Once you see every chord as a triad first and colour notes second, the fretboard stops being a forest and starts being a map.