Dominant 7 Chord Extensions - Infographic With Guitar Neck Diagrams

What's A Dominant 7 Chord?

A dominant 7 chord, often denoted as "dom7" or simply "7," is a type of four-note chord commonly used in music, especially in jazz and blues. Basically, it is built upon the fifth degree (the dominant) of a diatonic scale. However it is also present in other scales as Harmonic Minor, Melodic Minor and Harmonic Major.

In a dominant 7 chord, you have the following notes:

•  Root (R) - This is the starting note or the tonic of the chord.
• Major Third (3) - It is the third note starting from the root.
• Perfect Fifth (5) - It is the fifth note starting from the root.
• Minor Seventh (b7) - This is a lowered seventh note starting from the root.

The formula for constructing a dominant 7 chord is R-3-5-b7. For example, in the key of C major, the dominant 7 chord is G7. The notes in a G7 chord are G (the root), B (the major third), D (the perfect fifth), and F (the minor seventh). So, the G7 chord consists of the notes G, B, D, and F.

Dominant 7 chords have a strong, unresolved sound and are often used to create tension in music, leading to a resolution to a more stable chord, typically the tonic (I) chord. This tension-resolution quality makes them essential in creating musical dynamics and progressions.

Natural Extensions

A dominant 7 chord can be extended by adding additional notes on top of the basic chord tones (root, major third, perfect fifth, and minor seventh). These extended chords are often used in jazz and other genres to add complexity and color to the harmony.

Some common extensions for a dominant 7 chord include:

• Ninth (9) - This adds the second scale degree above the root. In C dominant 7, it would be D. The chord is then called a "Dominant 9" or "9" chord. So, for C9, the notes are C, E, G, Bb, and D.
• Eleventh (11) - This adds the fourth scale degree above the root. In C dominant 7, it would be F. The chord is called a "Dominant 11" or "11" chord. So, for C11, the notes are C, E, G, Bb, D, and F.
• Thirteenth (13) - This adds the sixth scale degree above the root. In C dominant 7, it would be A. The chord is then called a "Dominant 13" or "13" chord. So, for C13, the notes are C, E, G, Bb, D, and A.

When you use these extensions, it's important to consider the voicing of the chord, as including all these notes in a single chord voicing might not be practical on some instruments, like the guitar or piano. Musicians often use different voicings or omit certain notes to make the chord more playable and sound more harmonically pleasing.

Additionally, the choice of extensions can affect the overall color and tension of the chord, providing various harmonic options for creating interesting chord progressions and improvisations in music.

Altered Extensions

In addition to the natural extensions (9, 11, and 13) for dominant 7 chords previously discussed, you can also include altered extensions to add further tension and color to the chord. These alterations typically involve changing the natural extensions by raising or lowering them. Here are some common altered extensions for dominant 7 chords: 

•  Flat Ninth (b9) - This lowers the ninth degree by a half step. In C dominant 7, it would be Db. The chord is then called a "Dominant 7(b9)" or "7b9" chord. So, for C7b9, the notes are C, E, G, Bb, and Db.
• Sharp Ninth (#9) - This raises the ninth degree by a half step. In C dominant 7, it would be D#. The chord is called a "Dominant 7(#9)" or "7#9" chord. So, for C7#9, the notes are C, E, G, Bb, and D#.
• Sharp Eleventh (#11) - This is the same note as the b5. The perfect fourth is raised by a halh-step. In C dominant 7, it would be F#. The chord is called a "Dominant 7(#11)" or "7#11" chord. For C7#11, the notes are C, E, G, Bb, D, and F#.
• Flat Thirteenth (b13) - This lowers the thirteenth degree by a half step. In C dominant 7, it would be Ab. The chord is called a "Dominant 7(b13)" or "7b13" chord. So, for C7b13, the notes are C, E, G, Bb, D, and Ab.

These altered extensions create a more dissonant and tense sound and are often used in jazz and other genres to add richness and complexity to chord progressions and improvisations. The choice of which altered extensions to use depends on the specific harmonic context and the desired musical effect.

Guitar Chord Shapes

The two guitar shapes below show the positios of the extensions for two dominant 7 chords positions with root (R) on E and A string.