Dominant Seventh Chord

Understanding the Dominant Seventh Chord

The dominant seventh chord is one of the most important and frequently used chords in Western music. Built on the fifth degree of a scale, it creates tension that strongly resolves to the tonic, making it essential for establishing key centers and driving harmonic motion.

Structure of the Dominant Seventh

A dominant seventh chord consists of four notes:

• Root: The foundation note (e.g., G in G7)
• Major third: Creates the major quality (e.g., B in G7)
• Perfect fifth: Provides stability (e.g., D in G7)
• Minor seventh: Creates the characteristic tension (e.g., F in G7)

Harmonic Function

The dominant seventh chord serves crucial harmonic functions:

• Tension creation: The tritone between 3rd and 7th creates instability
• Resolution tendency: Strongly pulls toward the tonic chord
• Key establishment: Clearly defines the tonal center
• Cadential force: Essential in authentic cadences (V7-I)

Voice Leading Tendencies

The dominant seventh has strong voice leading tendencies:

• Leading tone (3rd): Resolves up by semitone to tonic
• Seventh: Resolves down by semitone to the third of tonic
• Fifth: Often moves down by step or stays common
• Root: Usually moves down by fifth to tonic root

Common Progressions

Dominant sevenths appear in many standard progressions:

• V7-I: Authentic cadence (G7-C)
• ii-V7-I: Jazz standard progression (Dm-G7-C)
• I-V7: Establishing dominant (C-G7)
• V7/V: Secondary dominant (D7 in key of C)

Jazz Extensions and Alterations

In jazz, dominant sevenths are often extended or altered:

• 9th chords: G7(9) adds the ninth (A)
• 11th chords: G7(11) includes the eleventh (C)
• 13th chords: G7(13) incorporates the thirteenth (E)
• Altered dominants: G7alt with ♭9, #9, ♭5, #5

Inversions and Voicings

Dominant sevenths can be voiced in different inversions:

• Root position: G-B-D-F
• First inversion: B-D-F-G
• Second inversion: D-F-G-B
• Third inversion: F-G-B-D

Recognition and Practice

To develop familiarity with dominant sevenths:

• Practice the V7-I resolution in all keys
• Listen for the characteristic "bluesy" sound
• Study blues progressions where they're prominent
• Practice voice leading from V7 to I
• Explore jazz standards with ii-V7-I progressions

Historical Context

The dominant seventh evolved through music history:

• Baroque: Used primarily as resolution chord
• Classical: Became standard in cadential formulas
• Romantic: Extended and chromatically altered
• Jazz/Blues: Became a stable sonority in its own right

Understanding the dominant seventh chord is crucial for harmonic analysis, composition, and improvisation across all musical styles.