A major
Major key. Scale: A, B, C#, D, E, F#, G#.
Octaves
Musical context
How the key relates to the chord, scale, mode and progression.
Theory
General info
- Name
- A major
- Mode
- Major
- Tonic
- A
- Key signature
3 sharps: C, F, G.
- Key character
- Scale degree 3 clearly distinguishes major from the parallel minor, while the leading tone strengthens V–I resolution. In equal temperament, tonic pitch alone does not determine mood; melody, harmony, register, tempo, and texture do.
- Overview
- The A major key sets its stable tones and typical harmonic connections. Major keys are built on the Ionian mode (steps 2 – 2 – 1 – 2 – 2 – 2 – 1), minor keys on the Aeolian (2 – 1 – 2 – 2 – 1 – 2 – 2). The number of accidentals marks the key's position on the circle of fifths.
Key composition
1Aroot
2Bmajor 2nd
3C#major 3rd
4Dperfect 4th
5Eperfect 5th
6F#major 6th
7G#major 7th
Key construction
- Interval formula
- AWBWC#HDWEWF#WG#
- Explanation
- The major scale follows the pattern whole, whole, half, whole, whole, whole, half. Its degrees form the key’s diatonic chords, while scale degree 3 defines the major quality.
Related keys
- Relative key
- F# minor
- Parallel key
- A minor
- Reference mode
- A Ionian (major)
Harmonic functions
TTonicI (A), iii (C#m), vi (F#m)
SSubdominantii (Bm), IV (D)
DDominantV (E), vii° (G#dim)
- Overview
- Tonic is the stable centre of a key. Predominant function moves away from tonic and prepares dominant; dominant points toward resolution in tonic. The scheme Tonic → Predominant → Dominant → Tonic describes a basic functional progression but does not exhaust tonal harmony.
Chords by degree
Primary triads
- Tonic triad 1 – 3 – 5
- Subdominant triad 4 – 6 – 1
- Dominant triad 5 – 7 – 2
A—C#—E
D—F#—A
E—G#—B
Tensions & resolutions
VIIG#G#
IAA
In typical voice leading, the leading tone rises by semitone to tonic.
IVDD
IIIC#C#
In dominant harmony, scale degree 4 normally falls by semitone to 3.
IIBB
IAA
Scale degree 2 may resolve downward by step to tonic.
Harmonic context
A major is a major key. Diatonic chords are built on its seven scale degrees, and functional motion commonly connects tonic, predominant, and dominant.
Natural progressions
Cadences
VEE
IAA
An authentic cadence resolves dominant function into tonic.
IVDD
VEE
IAA
A complete functional progression connects predominant, dominant, and tonic.
This key on guitar 🎸
See how A major looks on guitar.
Circle of fifths
Usage & Practice
Application in music
- Major-key diatonic chords support motion among tonic, predominant, and dominant without leaving the key.
- The authentic V – I progression emphasises the tonal centre through the leading tone and resolution of the dominant tritone.
- Patterns such as I – V – vi – IV can be transposed into this key without changing scale-degree relationships.
- Musical character depends not only on mode and tonic but also on melody, rhythm, register, tempo, texture, and timbre.
Practice
- Play the tonic chord (A), then compare it with the other diatonic chords: tonic serves as the stable centre of the key.
- Alternate A and E (I – V – I), focusing on the leading tone resolving to tonic.
- Add D (IV): play D – E – A to hear predominant–dominant–tonic motion.
- Sing the key's scale, emphasizing degrees I, III and V — these are the anchor notes.
- Improvise a melody starting and ending on the tonic to reinforce the sense of center.
Keyboard Trainer
Reinforce it in practice — play and name notes on the interactive keyboard.