There are 3 types of commonly used 9th guitar chords:
Dominant 9th (9), Major 9th (maj9), and Minor 9th (m9), are all derived from the dominant 7th, major 7th and minor 7th chords respectively.
| Chord | Description | Formula |
|---|---|---|
| Dom 9th | A dominant 7th chord with an added 9th (C7/9 or C9) | 1 - 3 - 5 - ♭7 - 9 |
| Major 9th | A major 7th chord with an added 9th (Cmaj7/9 or Cmaj9) | 1 - 3 - 5 - 7 - 9 |
| Minor 9th | A minor 7th chord with an added 9th (Cm7/9 or Cm9) | 1 - ♭3 - 5 - ♭7 - 9 |
If a chord with a symbol 9 is not preceded by the words maj or M, e.g., C9 & Cm9 as opposed to Cmaj9 or CM9, the 7th is always a dominant 7th (♭7).
This session features Dominant 9th chords.
| 9th | A | B♭ | B | C | C# | D | E♭ | E | F | F# | G | A♭ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Root | A | B♭ | B | C | C# | D | E♭ | E | F | F# | G | A♭ |
| Major 3rd | C# | D | D# | E | E#(F) | F# | G | G# | A | A# | B | C |
| Perfect 5th | E | F | F# | G | G# | A | B♭ | B | C | C# | D | E♭ |
| Minor 7th | G | A♭ | A | B♭ | B | C | D♭ | D | E♭ | E | F | G♭ |
| Major 9th | B | C | C# | D | D# | E | F | F# | G | G# | A | B♭ |
Please Note: With chords like A9 (first position), although it shows a barre over strings 2, 3, and 4 with the first finger, you will naturally barre strings 1, 2, 3 & 4 with the first finger... and that's OK. It is simply illustrated like this so that you don't see 2 dots (fingers) on the same string. The second finger on the 3rd fret (first string) overides the first finger on the second fret (first string)... much easier.
Dominant 9th chords, often denoted as "dom9" or "9" chords, are essential elements of music theory and harmony.
Extension of Dominant 7th Chords: Dominant 9th chords are built upon dominant 7th chords. A dominant 7th chord consists of the root, major third, perfect fifth, and minor seventh. The dominant 9th chord adds an additional major ninth interval to this configuration.
Full Structure: A dominant 9th chord consists of the root, major third, perfect fifth, minor seventh, and major ninth intervals. For example, a G9 chord includes the notes G, B, D, F, and A.
Jazz and Blues Foundation: Dominant 9th chords are extensively used in jazz and blues music. They add richness, color, and harmonic complexity to chord progressions, making them a staple in these genres.
Tension and Resolution: The addition of the major ninth interval to the dominant 7th chord introduces tension into the chord. This tension can create a strong desire for resolution to a consonant chord, such as a major chord or a tonic chord.
Altered Tensions: In some cases, dominant 9th chords can have altered tensions, such as a flat ninth (b9) or sharp ninth (#9). These alterations contribute to a more complex and dissonant sound, often used in jazz improvisation and fusion music.
Voice Leading: Dominant 9th chords offer interesting voice-leading possibilities due to the close intervals between their components. Notes can be smoothly moved to adjacent notes in other chords, creating smooth and melodic transitions.
Chord Inversions: Like other chords, dominant 9th chords can be inverted to change the order of the notes. These inversions can lead to unique harmonic progressions and basslines.
Alternative Voicings: Guitarists and keyboard players often explore various voicings for dominant 9th chords. These different fingerings on the instrument can produce varying tonal qualities and facilitate smoother chord transitions.
Substitute for Dominant 7th Chords: Dominant 9th chords can sometimes be used as substitutes for dominant 7th chords. They offer a richer sound and can help add variety to chord progressions.
Chord Extensions: The dominant 9th chord is one example of a chord extension, where additional notes beyond the basic triad are used. Other extensions, like the 11th and 13th, can further expand the harmonic possibilities.
Fusion and Contemporary Music: Apart from jazz and blues, dominant 9th chords are also utilized in contemporary and fusion music. Their versatility allows them to fit into various genres and musical styles.
