How to Build Any Chord from Scratch

Chords are the vertical building blocks of music. While melodies move horizontally through time, chords stack notes on top of each other to create harmony. If you understand how chords are built, you can construct any chord in any key without relying on memorization or chord charts. The underlying principle is elegant: nearly every chord is built by stacking intervals of a third.

The Foundation: Intervals You Need to Know

Before building chords, you need two intervals in your toolkit:

• Major third (M3): four half steps. Example: C to E.
• Minor third (m3): three half steps. Example: C to E-flat.

That is it. With just these two intervals, you can build every standard triad and seventh chord.

Triads: Three-Note Chords

A triad is the simplest chord — three notes stacked in thirds. There are four types, each defined by the order in which you stack major and minor thirds.

Major Triad (M3 + m3)

Start with the root, add a major third, then add a minor third on top of that.

C major triad: C - E - G

• C to E: major third (4 half steps)
• E to G: minor third (3 half steps)
• Total span from C to G: perfect fifth (7 half steps)

The major triad sounds stable, bright, and resolved. It is the most common chord type in Western music.

Minor Triad (m3 + M3)

Reverse the order: start with a minor third, then a major third.

C minor triad: C - E-flat - G

• C to E-flat: minor third (3 half steps)
• E-flat to G: major third (4 half steps)
• Total span: still a perfect fifth

The minor triad sounds darker and more introspective than its major counterpart, but it is equally stable. Notice that the only difference between C major and C minor is the third: E vs. E-flat.

Diminished Triad (m3 + m3)

Stack two minor thirds.

C diminished triad: C - E-flat - G-flat

• C to E-flat: minor third
• E-flat to G-flat: minor third
• Total span: diminished fifth, also called a tritone (6 half steps)

The diminished triad sounds tense and unstable, like it urgently needs to resolve somewhere. In a major key, it naturally occurs on the seventh scale degree (B diminished in C major: B - D - F).

Augmented Triad (M3 + M3)

Stack two major thirds.

C augmented triad: C - E - G-sharp

• C to E: major third
• E to G-sharp: major third
• Total span: augmented fifth (8 half steps)

The augmented triad has a shimmering, unresolved quality. It appears less frequently than major and minor triads but is a favorite in jazz, film scores, and Beatles songs (“Oh! Darling” uses augmented chords prominently).

A Quick Reference Table

Chord Type	Formula	Example (root = C)	Sound
Major	M3 + m3	C - E - G	Bright
Minor	m3 + M3	C - Eb - G	Dark
Diminished	m3 + m3	C - Eb - Gb	Tense
Augmented	M3 + M3	C - E - G#	Shimmering

Seventh Chords: Adding a Fourth Note

Seventh chords extend a triad by stacking one more third on top, adding a fourth note. This creates richer, more colorful harmony. There are five common seventh chord types.

Major 7th (Maj7)

Take a major triad and add a major third on top.

Cmaj7: C - E - G - B

The interval from the root to the seventh is a major seventh (11 half steps). Major 7th chords sound lush, warm, and sophisticated. They are a staple of jazz, bossa nova, and R&B. Think of the opening chord of Stevie Wonder’s “You Are the Sunshine of My Life.”

Dominant 7th (7)

Take a major triad and add a minor third on top.

C7: C - E - G - B-flat

The interval from root to seventh is a minor seventh (10 half steps). Despite using a major triad as its base, the dominant 7th chord contains a tritone between its third and seventh (E to B-flat), which creates tension that wants to resolve. In classical harmony, the dominant 7th chord (built on scale degree V) resolves to the tonic. G7 resolves to C major. This V-I resolution is the most fundamental harmonic motion in tonal music.

Minor 7th (m7)

Take a minor triad and add a minor third on top.

Cm7: C - E-flat - G - B-flat

Both the third and seventh are minor intervals from the root. Minor 7th chords sound mellow and open. They dominate jazz, neo-soul, and lo-fi hip hop.

Half-Diminished 7th (m7b5)

Take a diminished triad and add a major third on top.

Cm7b5 (also written C half-diminished): C - E-flat - G-flat - B-flat

This chord appears naturally on the seventh degree of a major key (Bm7b5 in C major) and on the second degree of a minor key (Dm7b5 in C minor). It functions as a pre-dominant chord in minor-key ii-V-i progressions, which are everywhere in jazz.

Diminished 7th (dim7)

Take a diminished triad and add a minor third on top.

Cdim7: C - E-flat - G-flat - B-double-flat (enharmonically A)

Every note in a diminished 7th chord is separated by a minor third, dividing the octave into four equal parts. This symmetry means there are really only three distinct diminished 7th chords — all the rest are inversions. The sound is dramatic and suspenseful, frequently used in classical music, film scores, and as a passing chord in jazz.

The Chord Formula Approach

Instead of thinking in stacked thirds, some musicians prefer to think in terms of scale degrees or semitone distances from the root. Here are the formulas:

• Major: 1 - 3 - 5
• Minor: 1 - b3 - 5
• Diminished: 1 - b3 - b5
• Augmented: 1 - 3 - #5
• Maj7: 1 - 3 - 5 - 7
• Dom7: 1 - 3 - 5 - b7
• Min7: 1 - b3 - 5 - b7
• Half-dim7: 1 - b3 - b5 - b7
• Dim7: 1 - b3 - b5 - bb7

The “1” is the root, “3” is the major third of the scale, “b3” is the minor third, and so on. If you know your major scale for any root note, you can apply these formulas instantly.

Building Chords in Any Key: A Worked Example

Let us build an F-sharp dominant 7th chord (F#7) from scratch.

1. Start with the F-sharp major scale: F# - G# - A# - B - C# - D# - E# - F#
2. Apply the dominant 7th formula: 1 - 3 - 5 - b7
3. Pick out the notes:
   • 1 = F#
   • 3 = A# (the third degree of F# major)
   • 5 = C# (the fifth degree)
   • b7 = E (lower the seventh degree E# by a half step)

F#7 = F# - A# - C# - E

The process works for any chord type in any key. Know the major scale, apply the formula, done.

Inversions: Same Notes, Different Bass

A chord does not always have its root as the lowest note. When a different chord tone is in the bass, the chord is inverted:

• Root position: root on the bottom (C - E - G)
• First inversion: third on the bottom (E - G - C)
• Second inversion: fifth on the bottom (G - C - E)
• Third inversion (7th chords only): seventh on the bottom (B-flat - C - E - G)

Inversions do not change the chord’s name or function, but they change its voice leading and how smoothly it connects to the next chord. Skilled arrangers use inversions to create smooth bass lines where the bass note moves by step rather than leaping.

Practical Tips for Internalizing Chord Construction

Start with one key. Build all four triad types and all five seventh chord types from C. Then move to G, then D, following the circle of fifths. By the time you reach F-sharp, you will have covered every key.

Use a keyboard. Even if you are primarily a guitarist or singer, a piano keyboard makes chord construction visual. You can see the half steps and whole steps laid out physically.

Spell chords out loud. Say “D minor seven: D, F, A, C” before you play it. Engaging your verbal memory alongside your muscle memory accelerates learning.

Analyze songs you love. Take a chord progression from a favorite song and identify each chord’s type. Is that an Am7? A Gmaj7? A D7? Connecting theory to music you already care about makes the knowledge stick.

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Build your chord vocabulary hands-on with Music Genius. The Build the Chords game gives you a target chord and asks you to select the correct notes, helping you internalize chord formulas through active practice rather than passive reading.