What is the formula for a minor triad?

A minor triad is built from the root (R), the minor third (b3), and the perfect fifth (5). The only difference from a major triad is that the third is lowered by one semitone.

Where do minor triads appear in a major key?

In a major key, the ii, iii, and vi chords are minor triads. For example, in C major: Dm (ii), Em (iii), and Am (vi) are all minor triads.

How do you extract minor triads from the CAGED system?

The same way as major triads: find the CAGED shape for the minor chord, then select only three adjacent strings containing the root, minor third, and fifth.

Minor Triads on Guitar

In the major triads article we looked at why triads are an essential tool for any guitarist who wants to compose, arrange, or simply fit into a band. There we worked with major triads — built from R - 3 - 5 (root, major third, and perfect fifth).

Now it's time for minor triads. The good news is that the difference from major is minimal: only one note changes. The formula for a minor triad is R - b3 - 5. We take the major third and lower it by one semitone. That's it. That single semitone is what gives minor chords their melancholic, dark, or introspective character.

Where minor triads appear

If you're working within a major key, minor triads appear naturally on three scale degrees: the ii, the iii, and the vi. For example, in the key of C major:

Dm (ii) — D, F, A
Em (iii) — E, G, B
Am (vi) — A, C, E

So every time you see a minor chord in a tonal progression, you're looking at a minor triad. They're just as important as major triads — in fact, in many styles (pop, R&B, neo-soul) progressions revolve around minor chords more than major ones.

The interval formula

Let's compare the two triads so the difference is crystal clear:

Major triad = major third + minor third (4 semitones + 3 semitones)
Minor triad = minor third + major third (3 semitones + 4 semitones)

Notice: the total sum is the same (7 semitones = perfect fifth), but the order of the intervals is reversed. In a major triad the larger interval comes first; in a minor triad the smaller one comes first. That one-semitone difference in the third completely changes the color of the chord.

Let's use A minor as our example. The notes are:

A (root / R)
C (minor third / b3) — 3 semitones above A
E (perfect fifth / 5) — 4 semitones above C

If it were A major, the third would be C# instead of C. Only that one note changes.

Example progression: i - iv - v in A minor

Let's use a classic minor-key progression: Am - Dm - Em (i - iv - v). First, here's how these chords look in common open shapes:

And the same progression using barre chords, which give you more mobility on the neck:

Just like with major triads, when two guitars play these full-string chords they step on each other's harmonic space. This is where minor triads save the day.

CAGED shapes for A minor

Just as we did with major triads, the first step is to locate the A minor chord across the entire fretboard using the CAGED system. Each shape gives us a different position of the same chord:

These four positions cover most of the fretboard. Notice that the Dm and Cm shapes are partial — in practice you don't always need all six strings, and for triads you'll only use three, so it doesn't matter.

Extracting minor triads

Now for the important part: pulling out three-string triads from the CAGED shapes. The process is the same as with major triads: pick three adjacent strings and keep only the root (R), minor third (b3), and fifth (5).

We'll extract triads from three different CAGED shapes. Each row shows the reference shape on the left and the triad extractions on the right:

Let's break down what we're seeing:

In the Em shape (fret 5), the strings 1-2-3 triad gives us C (b3), E (5), and A (R) — that's the Am triad in first inversion. The strings 2-3-4 triad gives us A (R), C (b3), and E (5) — root position.
In the Am shape (open), the strings 1-2-3 triad gives us A (R), C (b3), and E (5) — root position. The strings 2-3-4 triad gives us E (5), A (R), and C (b3) — second inversion.
In the upper fret area (frets 7-10), the strings 1-2-3 triad from the Dm shape gives us E (5), A (R), and C (b3) — second inversion. The strings 2-3-4 triad from the Cm shapegives us C (b3), E (5), and A (R) — first inversion.

Notice something key: each extraction gives you a different inversion of the same triad. That means you have several ways to play exactly the same three notes but in different positions on the neck and with a different voicing. This gives you options to move smoothly between chords without jumping all over the fretboard.

Quick comparison: major vs. minor

To see the direct relationship, here are the A major and A minor triads side by side in the same area of the neck. Notice that only one fret changes (the third):

One fret. From 6 to 5 on the fourth string: the major third (C#) drops to the minor third (C). Keep that in mind — when you're on stage and need to switch from major to minor quickly, it's just one finger moving one fret.

Practical tips

Now that you know the theory and the shapes, here are some tips to make minor triads actually useful in your playing:

Use them as a second guitar: if the rhythm guitar is playing full chords, you can play minor triads on the treble strings to add color without stepping on their space. This is especially effective in quiet sections or bridges.
Connect positions: practice moving triads up and down the neck following the CAGED system. When you've mastered the three positions for strings 1-2-3 and the three for strings 2-3-4, you'll be able to move across the entire fretboard without losing the chord.
Arpeggiation and fingerpicking: minor triads sound beautiful when arpeggiated. Three notes, three strings, a clean and emotional sound. Perfect for intros and soft sections.
Mix major and minor: in a progression like I - vi - IV - V (for example, C - Am - F - G), you can alternate major and minor triads on the treble strings while the rhythm guitar plays full chords. The result is far more interesting than having two guitars doing the same thing.
Watch your tuning: when playing only three notes, any tuning issues become much more noticeable. Make sure your guitar is properly tuned and the intonation is correct, especially on higher frets.

What's next

You now have both major and minor triads under your fingers. With those two you cover the vast majority of chords you'll encounter in any progression. But there are still important pieces to cover: diminished triads (which appear on the vii degree of the major scale) and dominant seventh chords, which are fundamental in blues, jazz, and any music that needs tension and resolution.

If you haven't read the major triads article yet, I'd recommend starting there: Triads: why are they so important?. It's the foundation everything in this article builds on.