The A dominant 7th chord (A7) is built from a root note (A), a major third (C#), a perfect fifth (E) and a minor seventh (G):
- Type: major tetrad.
- Formule: 1 3 5 ♭7.
- Music notes: A (1) C# (3) E (5) G (♭7).
- Chords to play with: IVmaj7 (Dmaj7) y V7 (Em7).
A7 chord [Musical explanation]
The A dominant seventh chord is a tetrad with formula 1 – 3 – 5 – ♭7. Therefore, to build it we need A (1), C# (3), E (5) and G (♭7):
This is due to the fact that a dominant seventh chord is made up of 3 third intervals:
- A major interval (4 half steps between the 3rd and root).
- A minor interval (3 half steps between the 5th and 3rd).
- A minor interval (3 half steps between the 7th and 5th).
If we apply this principle to the A7 chord we obtain that:
- C# is the major third of A because it is 4 half steps above the root.
- E is the perfect fifth of A because it is 3 half steps above the 3rd.
- G is the major seventh of A because it is 3 half steps above the 5th.
Thus, this confirms that a major seventh chord is defined by:
Root (A) – Major Third (C#) – Perfect Fifth (E) – Minor Seventh (G)
To sum up, in order to build the A7 chord we need to add the minor seventh (7th) to the A major chord.
A7 Guitar Chord
The A7 chord guitar has the following shape on the fretboard:
Let’s analyze in detail this chord diagram above to make sure that we understand how to play the A7 on guitar.
Let’s start by analyzing the 2 circles in blue, which indicate that on the strings 4 (D) and 2 (B) we have to place the fingers 1 (index) and 3 (ring finger). Note by the way the number 1 in black on the left that indicates on which fret we start playing the chord.
On the other hand, at the top we see that we have the characters:
X A E G C# E
This simply means that in the:
- Sixth string there is no sound.
- Fifth string sounds the A note.
- Fourth string sounds the E note.
- Third string sounds the G note.
- Second string sounds the C# note.
- First string sounds the E note.
And at the bottom we find the numbers:
1 5 ♭7 3 5
This indicates that in the:
- Sixth string There is no number because there is no sound.
- Fifth string sounds the root (1).
- Fourth string sounds the perfect fifth (5).
- Third string sounds the minor seveth (♭7).
- Second string sounds the major third (3).
- First string sounds the perfect fifth (5).
⚠️ Important: it is not mandatory to memorize all this information to play the A7 chord on guitar. But it is highly recommended to know it in order to understand the musical theory behind each chord.
Other ways to play the A dominant 7 guitar chord
In addition to the diagram shown at the beginning of the article, we can also find the A7 chord in the following fretboard positions:
A7 chord inversions
The 3 inversions of the A 7th chord are:
- First inversion: A7/C#.
- Second inversion: A7/E.
- Third inversion: A7/G.
A7 Ukulele Chord
Here you can see as well the A7 uke chord diagram:
A7 Piano Chord
To play the A7 chord on piano we only need to find the same music notes on its keys:
First Inversion (Amaj7/C#)
Second Inversión (Amaj7/E)
Third Inversión (Amaj7/G)
Music scales in which the A minor 7th chord can be found
- D major scale (armonizada por cuatríadas)
- Dmaj7 Em7 Gbm7 Gmaj7 A7 Bm7 Dbm7b5
- B natural minor scale (armonizada por cuatríadas)
- Bm7 Dbm7b5 Dmaj7 Em7 Gbm7 Gmaj7 A7
- D harmonic minor scale (armonizada por cuatríadas)
- Dm(maj7) Em7b5 Fmaj7#5 Gm7 A7 Bbmaj7 Dbdim7
- E melodic minor scale (armonizada por cuatríadas)
- Em(maj7) Gbm7 Gmaj7#5 A7 B7 Dbdim7 Ebm7b5
- D melodic minor scale (armonizada por cuatríadas)
- Dm(maj7) Em7 Fmaj7#5 G7 A7 Bdim7 Dbm7b5
A7 Chord PDF
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