A Dominant 7th
Hear the A Dominant 7th chord played for you.
A7
A – C♯ – E – G
Formula:R-M3-P5-m7
Intervals:P1-M3-P5-m7
Scale Degrees:1-3-5-b7
Introduction
The A Dominant 7th chord is a four-note chord made up of A, C♯, E, and G. It is built from a root, major third, perfect fifth, and minor seventh.
The A Dominant 7th piano chord (A7) consists of the notes A, C#, E, G. It is a major triad with an added minor 7th, giving it a bluesy, tense sound that strongly wants to resolve. Formula: R-M3-P5-m7 | Scale degrees: 1-3-5-b7.
Notes
A Dominant 7th Inversions
| Position | Notes |
|---|---|
| Root Position | A – C♯ – E – G |
| 1st Inversion | C♯ – E – G – A |
| 2nd Inversion | E – G – A – C♯ |
| 3rd Inversion | A – C♯ – E – G |
Key Signature
The key of A Dominant 7th has 3 sharps.
F♯C♯G♯
Order of sharps
Sharps are added to a key signature in a fixed order. Each new sharp key adds the next sharp on the list.
F♯C♯G♯D♯A♯E♯B♯
Mnemonic: Father Charles Goes Down And Ends Battle
Chords in the Key of A Major
These are the diatonic triads built on each degree of the A major scale:
C
D
E
F
G
A
B
C
D
E
F
G
A
B
I — A Major (major)
Theory: Intervals
Formula: R-M3-P5-m7
Intervals: P1-M3-P5-m7
The A Dominant 7th is built by stacking intervals from the root note. The formula R-M3-P5-m7 describes the scale degrees used. The intervals P1-M3-P5-m7 show the distance between each note in the chord.
A Dominant 7th — Frequently Asked Questions
What notes are in the A Dominant 7th chord?
The A Dominant 7th chord (A7) contains four notes: A (root), C# (major third), E (perfect fifth), and G (minor seventh). The major triad with a minor seventh creates the bluesy tension and forward drive that defines the dominant 7th sound.
How does A Dominant 7th differ from A Major?
A Major contains three notes: A, C#, E. A Dominant 7th adds a G (minor seventh) on top. That single note transforms a stable, resolved chord into one with strong forward motion — it wants to resolve down a fifth to D Major.
What does 'dominant' mean in music theory?
'Dominant' refers to the fifth scale degree. The dominant 7th chord is built on the fifth note of a key and contains a tritone that creates strong pull toward resolution. A7 is the dominant chord in D Major, one of the most common keys in popular music.
How is A Dominant 7th used in music?
A7 resolves to D Major in a V7–I cadence. It is one of the most used dominant 7th chords in blues, rock, and country music. A7 is also the V7 chord in a blues in D and appears as a secondary dominant (V7/V) in the key of G.
What songs use dominant 7th chords?
Dominant 7th chords are the backbone of blues and early rock: every chord in a standard 12-bar blues is a dominant 7th. Hit the Road Jack (Ray Charles), Ain't Misbehavin' (Fats Waller), and countless jazz standards rely on dominant 7th movement for their harmonic drive.
What is the tritone in A Dominant 7th?
The tritone in A7 is the interval between C# (the third) and G (the seventh) — exactly 6 semitones apart. This unstable interval gives A7 its strong pull toward D. The C# resolves up to D and the G resolves down to F#.
Practice Tips
- Play A Major then add G — hear how that one note creates urgency and forward motion.
- The tritone between C# and G is the engine of A7. Play just those two notes, then resolve: C# up to D, G down to F#. This is V7–I voice leading in D Major.
- Practice A7 → D Major until it is automatic in every inversion. This resolution appears in rock, country, blues, and folk constantly.
- A7 is the V chord in a blues in D: D7–D7–D7–D7–G7–G7–D7–D7–A7–G7–D7–A7. Practice the full 12-bar form.
- Compare A7 with Am7 — the major third (C#) gives A7 its bright, driving character, while Am7 with its minor third has a smoother, mellower quality.
- Rootless voicing: play C#–E–G without the A — this three-note voicing works for jazz comping when a bassist handles the root.
Related Tools
Chord FinderLook up any chord — see the notes, hear it, and play along.Chord DrillTimed drills to build speed and recognition across all chord types.Practice RoomPlug in a MIDI keyboard and get real-time feedback on every chord and scale.Circle of FifthsVisualize key relationships, relative minors, and key signatures.MIDI MonitorLive MIDI message stream with note names, velocity, and a scrolling staff.