A

A Major — the foundation triad — stable, bright, and the reference point every other chord colour is measured against.

The keys
C4C5C6
A – C♯ – E
What's inside A
NoteInterval from rootDegree
ARoot1
C♯Major 3rd3
EPerfect 5th5
Inversions
PositionKeys (low → high)
Root positionA4 – D♭5 – E5
1st inversionD♭5 – E5 – A5
2nd inversionE5 – A5 – D♭6
A working voicing

Split the chord between two hands the way working players do — a solid shell low down, the colour tones up top:

HandKeys
Left (shell)A2 – E3
Right (colour)D♭5 – E5
Where A lives

As the I chord

A → D → E → A

The classic I–IV–V–I motion with this chord as home.

In a ii–V–I

Bm7 → E7 → A

The strongest cadence in harmony, resolving onto this chord.

Put A under your fingers

Hear every voicing, see the keys light up, and drill it in the interactive Chord & Voicing Lab.

Open the Chord & Voicing Lab →
Major in every key
C C♯ D E♭ E F F♯ G A♭ B♭ B