Music Theory: Chords

Master harmony through systematic understanding of chord construction, function, and application

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Understanding Musical Chords

Chords are the harmonic foundation of music, created by combining three or more notes played simultaneously. They provide the emotional context, establish key centers, and create the harmonic progressions that drive songs forward. Master chord theory to unlock the secrets of harmony and composition.

What Are Musical Chords?

A chord is a combination of three or more different notes played together. Chords are built by stacking intervals, most commonly thirds, creating harmonic structures that support melodies and establish musical context. Understanding chords involves:

Chord Construction

  • Root note (foundation of the chord)
  • Intervals that determine chord quality
  • Extensions that add color and complexity
  • Inversions that change bass note and voicing

Harmonic Function

  • Tonic function (stability and rest)
  • Dominant function (tension and resolution)
  • Subdominant function (departure and movement)
  • Modal interchange and substitutions

Harmonic Functions

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Tonic Function

Provides stability and resolution

Common Chords:
I (Major)
vi (Minor)
iii (Minor)
Feeling:
Home, Rest, Stability
🚶

Subdominant Function

Creates departure from tonic

Common Chords:
IV (Major)
ii (Minor)
vi (Minor)
Feeling:
Movement, Departure

Dominant Function

Creates tension that wants to resolve

Common Chords:
V (Major)
V7 (Dom7)
vii° (Diminished)
Feeling:
Tension, Pull, Resolution

Chord Construction Fundamentals

Building Triads

Major Triad Formula

Root + Major 3rd + Perfect 5th

Example: C Major = C + E + G

Minor Triad Formula

Root + Minor 3rd + Perfect 5th

Example: A Minor = A + C + E

Diminished Triad Formula

Root + Minor 3rd + Diminished 5th

Example: B Diminished = B + D + F

Seventh Chords

Dominant 7th

Major Triad + Minor 7th

Creates strong pull to tonic

Minor 7th

Minor Triad + Minor 7th

Smooth, jazzy sound

Major 7th

Major Triad + Major 7th

Dreamy, ethereal quality

Essential Chord Types

☀️

Major Triads

M

Bright, stable, happy sound. Foundation of Western harmony.

Formula:
1 - 3 - 5
Intervals:
Root + Major 3rd + Perfect 5th
Mood:
Happy, Bright, Stable
Examples:
C Major (C-E-G)
G Major (G-B-D)
F Major (F-A-C)
🌙

Minor Triads

m

Darker, more emotional than major. Essential for expression.

Formula:
1 - ♭3 - 5
Intervals:
Root + Minor 3rd + Perfect 5th
Mood:
Sad, Emotional, Introspective
Examples:
A Minor (A-C-E)
E Minor (E-G-B)
D Minor (D-F-A)

Dominant 7th

7

Adds tension and color. Essential for blues, jazz, and rock.

Formula:
1 - 3 - 5 - ♭7
Intervals:
Major Triad + Minor 7th
Mood:
Bluesy, Tense, Driving
Examples:
G7 (G-B-D-F)
C7 (C-E-G-B♭)
A7 (A-C#-E-G)
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Minor 7th

m7

Smooth, jazzy sound. Perfect for sophisticated harmony.

Formula:
1 - ♭3 - 5 - ♭7
Intervals:
Minor Triad + Minor 7th
Mood:
Jazzy, Smooth, Sophisticated
Examples:
Am7 (A-C-E-G)
Dm7 (D-F-A-C)
Em7 (E-G-B-D)

Major 7th

maj7

Dreamy, ethereal quality. Common in jazz and neo-soul.

Formula:
1 - 3 - 5 - 7
Intervals:
Major Triad + Major 7th
Mood:
Dreamy, Ethereal, Sophisticated
Examples:
Cmaj7 (C-E-G-B)
Fmaj7 (F-A-C-E)
Gmaj7 (G-B-D-F#)
🔄

Suspended

sus

Neither major nor minor. Creates suspense and resolution.

Formula:
1 - 4 - 5 (sus4) or 1 - 2 - 5 (sus2)
Intervals:
Root + 4th/2nd + Perfect 5th
Mood:
Suspended, Floating, Anticipatory
Examples:
Csus4 (C-F-G)
Dsus2 (D-E-A)
Gsus4 (G-C-D)
⬇️

Diminished

dim

Tense and unstable. Used for dramatic effect and transitions.

Formula:
1 - ♭3 - ♭5
Intervals:
Root + Minor 3rd + Diminished 5th
Mood:
Tense, Dark, Unstable
Examples:
Bdim (B-D-F)
F#dim (F#-A-C)
Gdim (G-B♭-D♭)

Augmented

aug

Mysterious, whole-tone sound. Creates harmonic ambiguity.

Formula:
1 - 3 - #5
Intervals:
Root + Major 3rd + Augmented 5th
Mood:
Mysterious, Ambiguous, Floating
Examples:
Caug (C-E-G#)
Faug (F-A-C#)
Gaug (G-B-D#)
🎹

Extended Chords

9, 11, 13

Add 9ths, 11ths, and 13ths for rich, complex harmony.

Formula:
Add 9, 11, or 13 to basic triads and 7ths
Intervals:
Basic chord + upper extensions
Mood:
Complex, Rich, Modern
Examples:
Cmaj9 (C-E-G-B-D)
Am11 (A-C-E-G-D)
G13 (G-B-D-F-E)
🤘

Power Chords

5

The backbone of rock, punk, and metal. No 3rd means neither major nor minor.

Formula:
1 - 5
Intervals:
Root + Perfect 5th (+ Octave)
Mood:
Powerful, Raw, Aggressive
Examples:
E5 (E-B)
A5 (A-E)
G5 (G-D)
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Add Chords

add9

Add color tones to triads without the 7th. Shimmery, open sound.

Formula:
1 - 3 - 5 - 9 (no 7th)
Intervals:
Triad + added tone (no 7th)
Mood:
Open, Shimmery, Acoustic
Examples:
Cadd9 (C-E-G-D)
Gadd9 (G-B-D-A)
Dadd9 (D-F#-A-E)
🎺

Sixth Chords

6

Warm, resolved jazz and swing sound. Major triad plus the 6th.

Formula:
1 - 3 - 5 - 6
Intervals:
Major Triad + Major 6th
Mood:
Warm, Vintage, Resolved
Examples:
C6 (C-E-G-A)
G6 (G-B-D-E)
D6 (D-F#-A-B)
🌃

Minor Sixth

m6

Bittersweet sophistication. Essential in jazz minor and bossa nova.

Formula:
1 - ♭3 - 5 - 6
Intervals:
Minor Triad + Major 6th
Mood:
Bittersweet, Noir, Sophisticated
Examples:
Am6 (A-C-E-F#)
Dm6 (D-F-A-B)
Em6 (E-G-B-C#)
🔻

Half-Diminished

ø7 / m7♭5

The ii chord in minor keys. Essential for jazz minor progressions.

Formula:
1 - ♭3 - ♭5 - ♭7
Intervals:
Diminished Triad + Minor 7th
Mood:
Yearning, Unresolved, Jazz
Examples:
Bm7♭5 (B-D-F-A)
F#m7♭5 (F#-A-C-E)
Em7♭5 (E-G-B♭-D)
📐

Slash Chords

/

Inversions and bass note chords for smooth voice leading.

Formula:
Chord / Bass Note
Intervals:
Any chord with specified bass note
Mood:
Smooth, Flowing, Arranged
Examples:
C/E (1st inv.)
D/F# (walking bass)
Am/G (descending)
🎸

Dominant 9th

9

The funk chord. Rich dominant sound with the added 9th for groove.

Formula:
1 - 3 - 5 - ♭7 - 9
Intervals:
Dominant 7th + Major 9th
Mood:
Funky, Groovy, Soulful
Examples:
E9 (E-G#-B-D-F#)
A9 (A-C#-E-G-B)
G9 (G-B-D-F-A)
🌀

Altered Dominant

7alt

Maximum tension chords with altered 5ths and 9ths. The Hendrix chord lives here.

Formula:
1 - 3 - ♭5/#5 - ♭7 - ♭9/#9
Intervals:
Dominant 7th with altered extensions
Mood:
Tense, Chromatic, Expressive
Examples:
E7#9 (Hendrix chord)
A7♭9 (jazz tension)
G7#5 (augmented dom.)

Essential Chord Progressions

Chord progressions are the backbone of songs. These fundamental patterns appear across all genres and provide the harmonic framework for countless compositions.

I-V-vi-IV

C-G-Am-F

The most popular progression in Western music

Genres:

PopRockCountry

Famous Songs:

"Let It Be"
"Don't Stop Believin'"
"Someone Like You"

ii-V-I

Dm7-G7-Cmaj7

The cornerstone of jazz harmony

Genres:

JazzR&BNeo-Soul

Famous Songs:

"All The Things You Are"
"Autumn Leaves"
"Fly Me To The Moon"

I-vi-ii-V

C-Am-Dm-G

Circle of fifths progression

Genres:

JazzDoo-wopBallads

Famous Songs:

"Heart and Soul"
"Blue Moon"
"Stand By Me"

vi-IV-I-V

Am-F-C-G

Emotional pop progression

Genres:

PopAlternativeIndie

Famous Songs:

"Zombie"
"Basket Case"
"What's Up?"

Practice Exercises

Chord Construction

Build chords from scales and intervals

1
Choose a root note
2
Apply the chord formula
3
Practice on different strings
4
Play in different positions

Progression Practice

Master smooth chord transitions

1
Start with simple triads
2
Practice common progressions
3
Focus on smooth voice leading
4
Add rhythm and strumming

Function Analysis

Understand how chords work in context

1
Identify chord functions
2
Analyze favorite songs
3
Practice cadences
4
Experiment with substitutions

The Language of Harmony

Chords are more than just combinations of notes—they're emotional vocabularies that communicate feelings, create expectations, and guide listeners through musical journeys. Each chord type has its own character, and understanding these personalities helps you choose the right harmonic tools for your musical expression.

Daily Chord Study Routine

Theory Practice (15 min)

  • Build chords from different roots
  • Practice chord formulas and intervals
  • Analyze chord functions in songs
  • Study voice leading between chords

Practical Application (15 min)

  • Practice common chord progressions
  • Work on smooth chord transitions
  • Experiment with different voicings
  • Apply chords to favorite songs