AKA: A7, A Dom, Adom7, A Dominant 7th, A Dominant seventh
A7 Chord Chart
Dominant seventh chords can be constructed in several different ways, including by stacking thirds (a Major 3rd + minor 3rd + minor 3rd), or by using the interval of a minor seventh above the root of the chord.
For example: G7 = G, B, D, F (Root, 3rd, 5th, m7th) where G-B is a Major 3rd, B-D is a minor 3rd and D-F is a minor 3rd
These chords are often used to add color and interest to harmonic progressions. They can add tension and be resolved to create a sense of resolution and satisfaction. A II-V-I chord progression in the key of C, for example, would consist of a D minor (II), a G7 (V), and a C Major (I). The G7 chord creates tension that suggests the resolution to the C major chord, creating a sense of movement and direction in the progression.
Try to play a II-V-I as D min, G Maj, C Maj and then as D min, G7 and C Maj. Can you feel the difference? When you play the G7 chord, you should be able to hear the tension created by the F in the chord, which calls for resolution to the E in the following C major chord. This tension and resolution is what gives the II-V-I progression its sense of movement and direction.
7th Chord Buttons
The 7th chord buttons on Stradella bass system (dom 7th & dim 7th) play just the root, the 3rd, and the 7th.
In other words, dominant 7th and diminished 7th chords buttons on the Stradella bass system, don’t play the 5th.
To play a full dominant seventh chord, you would need to play the diminished chord one row above the root on the bass buttons as shown in the chart. This diminished chord, when played with the root of the dominant seventh chord, will provide the missing fifth and complete the chord.
Root + 7th chord: G + G7 = G + G, B, F (Root, 3rd, m7th)
Root + Dim chord: G + D dim = G + D, F, B (Root, 5th, m7th, 3rd)
A, C#, E, G
A7 button plays:
A, C#, G (no E)
R, 3°, 5°, m7°
7th chord buttons play:
R, 3°, m7° (no 5°)
Root + 7th chord: A7(omit5)
A + A7
(B♭♭ + B♭♭7)
Root + Dim chord: A7
A + E dim
(B♭♭ + F♭ dim)
4 + 2