Seventh Chords - maj7, 7, m7, m7b5, dim7 and More

Add one more third on top of a triad and you get a seventh chord: root, 3rd, 5th and 7th. That fourth note adds colour and, in some chords, a strong urge to move. Seventh chords are the everyday vocabulary of jazz, soul, R&B, bossa nova and a lot of pop - and the dominant seventh is just as central in classical music, blues and rock.

How seventh chords are built

A seventh chord is a triad plus a 7th above the root. Two things decide its name:

1. The triad underneath (major, minor, diminished or augmented).
2. The kind of 7th on top: major 7th (11 half steps above the root), minor 7th (10 half steps) or diminished 7th (9 half steps).

Watch the most common confusion: "7" on its own means a minor 7th (dominant seventh). Only "maj7" means a major 7th.

The five essential seventh chords

Major seventh (maj7)

Soft, warm, dreamy. The major 7th sits a half step below the octave, giving a gentle shimmer without tension.

• Symbols: Cmaj7, CM7, CΔ7
• Examples: Fmaj7 = F A C E, Gmaj7 = G B D F#, Ebmaj7 = Eb G Bb D.
• Function: the I and IV chords of a major key.

Dominant seventh (7)

Bluesy and restless. Between the 3rd and the b7 lies a tritone (B and F in G7), the most unstable interval in tonal music. It wants to resolve: in G7 to C, B rises to C and F falls to E.

• Symbol: C7
• Examples: G7 = G B D F, D7 = D F# A C, E7 = E G# B D, Bb7 = Bb D F Ab.
• Function: the V chord - it pulls strongly to the tonic. In blues, every chord can be a dominant seventh, used for colour rather than resolution.

Minor seventh (m7)

Mellow, smooth, relaxed - less dramatic than a plain minor triad.

• Symbols: Cm7, Cmin7, C-7
• Examples: Am7 = A C E G, Dm7 = D F A C, Em7 = E G B D, F#m7 = F# A C# E.
• Function: the ii, iii and vi chords of a major key; i in Dorian or Aeolian music.

Half-diminished (m7b5)

Dark and searching. A diminished triad with a minor 7th on top.

• Symbols: Cm7b5, Cø, Cø7
• Examples: Bm7b5 = B D F A, F#m7b5 = F# A C E, Dm7b5 = D F Ab C.
• Function: vii in a major key, and above all ii in a minor key: Bm7b5 - E7 - Am is the classic minor ii - V - i.

Diminished seventh (dim7)

Tense, dramatic, suspenseful. It stacks three minor thirds, so all four notes are equally spaced. Its 7th is a diminished 7th - enharmonically the same sound as a major 6th - which is why Cdim7 is spelled C Eb Gb Bbb but often played as C Eb Gb A.

• Symbols: Cdim7, C°7
• Examples: Bdim7 = B D F Ab, G#dim7 = G# B D F, C#dim7 = C# E G Bb.
• Function: vii°7 in harmonic minor (G#dim7 to Am), and as a passing chord between two chords a whole step apart (C - C#dim7 - Dm).

Because it is symmetrical, there are only three different dim7 sounds. Bdim7, Ddim7, Fdim7 and Abdim7 contain the same four pitches - only the spelling changes.

Other seventh chords worth knowing

Minor-major seventh (mMaj7)

A minor triad with a major 7th: C Eb G B. Mysterious, cinematic, unresolved. It is the i chord of the harmonic and melodic minor scales, and it appears in descending lines like Cm - CmMaj7 - Cm7 - Cm6, where one voice slides down by half steps (C, B, Bb, A).

• Symbols: CmMaj7, Cm(maj7), C-Δ7

7sus4

A dominant seventh with the 3rd replaced by the 4th: C F G Bb. It softens the dominant pull and is common in funk, soul and modal jazz.

Augmented seventh (7#5)

A dominant seventh with a raised 5th: C E G# Bb. The #5 pushes upward toward the 3rd of the next chord - C7#5 to F, where G# moves to A.

Sixth chords

C6 (C E G A) and Cm6 (C Eb G A) add a 6th instead of a 7th. They are not seventh chords, but they fill the same role as a richer tonic, especially in swing and older pop styles.

Seventh chords in a major key

Stacking four notes on each degree of the C major scale gives the same pattern in every major key:

There is only one dominant seventh per major key - on the 5th degree. That is why a dominant seventh points so clearly to its key. Listen to the most important seventh-chord progression of all, the ii - V - I:

On the bass

On bass, a seventh chord becomes a four-note arpeggio, 1-3-5-7. Learning the shapes for maj7, 7, m7 and m7b5 lets you outline any chord chart. Here is the ii - V - I in C, played in one area of the neck so the hand barely moves:

The same chord tones are the raw material of a walking bass line: root on beat 1, other chord tones on beats 2 and 3, and an approach note on beat 4. Hear a generated walking line over the ii - V - I:

Continue with arpeggios on the bass and walking bass.

Practice

1. Spell Cmaj7, C7, Cm7, Cm7b5 and Cdim7, then do the same on F, G and D. Check: Gm7b5 = G Bb Db F; Dmaj7 = D F# A C#; Fdim7 = F Ab Cb Ebb (usually played as F Ab B D).
2. Play C7 resolving to F, then G7 resolving to C. Watch the 3rd move up a half step and the 7th move down.
3. Play the ii - V - I in three keys: C, F and Bb.
4. Name: A C# E G, E G B D, F# A C E, D F# A C#. (Answers: A7, Em7, F#m7b5, Dmaj7.)

Tools and further study:

• Build and compare chords with the chord builder and check spellings with the chord identifier.
• Spelling drill: sevenths 1.
• Bass players: walk through changes with walking ii-V-I.
• Play ii - V - I in any key with the progression player.
• Print the chord formulas chart.
• Chord pages: Cmaj7, G7, Dm7, Bm7b5, Bdim7, CmMaj7.
• Related lessons: triads, chord inversions, diatonic harmony, cadences.