C major
C major is the major key on the tonic C. It needs no sharps or flats, consists only of natural notes and is therefore the standard key for getting to know the scale and diatonic chords. Its relative key A minor has exactly the same notes.
- Tonic
- C
- Key signature
- none
- Tonic chord
- C major, C–E–G
- Subdominant
- F major, F–A–C
- Dominant
- G major, G–B–D
- Leading tone
- B
- Relative key
- A minor
The scale without sharps or flats
The major scale follows the pattern whole, whole, half, whole, whole, whole, half. On the tonic C this gives nothing but natural notes, on the piano the white keys from C to C. That is why C major is written without a key signature. If you start the same pattern on G, you need an F♯ so that the semitone step falls in the right place.
C major scale
White keys only. The semitone steps lie between the third and fourth and between the seventh and eighth degree. The leading tone B is marked; it lies a semitone below the tonic and pulls upwards.
The chords of C major
If you build a triad on every degree using notes of the scale, seven chords arise. The order major–minor–minor–major–major–minor–diminished holds in every major key; only the notes change.
| Degree | Chord | Notes | Quality |
|---|---|---|---|
| I | C | C–E–G | major |
| ii | Dm | D–F–A | minor |
| iii | Em | E–G–B | minor |
| IV | F | F–A–C | major |
| V | G | G–B–D | major |
| vi | Am | A–C–E | minor |
| vii° | B° | B–D–F | diminished |
The three main functions are tonic (C), subdominant (F) and dominant (G). The progression I–V–vi–IV is C–G–Am–F in C major and carries countless songs. The detailed derivation is on the page Diatonic chords.
C major or A minor?
Both keys have no sharps or flats, because A minor is the relative key of C major. The ending decides: if the melody ends on C and the last chord is C major, the piece is in C major. An accidental in front of G (G♯), on the other hand, is a clear sign of A minor, because C major needs no G♯.
On the circle of fifths C major is at the top. Clockwise, G major adds a sharp, anticlockwise F major adds a flat.
Pieces in C major
These sheets are in the archive and are in C major. You can recognise the key by the empty key signature and the final chord.
Piano
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Präludium C-Dur Johann Sebastian Bach, BWV 846, The Well-Tempered Clavier I, No. 1 · piano · 2 pages
4/4 with no sharps or flats in the key signature. The piece consists of broken chords.
-
Invention Nr. 1 C-Dur Johann Sebastian Bach, BWV 772, from: Two-Part Inventions · piano · 2 pages
Two voices, no key signature. With an F♯ in the fourth bar a note outside the key appears briefly. The piece ends on a C major chord with a fermata.
-
Sonatine C-Dur Muzio Clementi, op. 36 No. 1 · piano · 3 pages
Headed “Spiritoso”, no key signature. The opening begins on the tonic C, and the first movement ends on C again in bar 38.
Common mistakes
- No sharps or flats, so always C major: A minor also has no sharps or flats. Only the ending and the tonic settle the key.
- Reading the F♯ in the invention as a change of key: A single accidental colours a spot but does not automatically mean a new key area.
- Spelling: The note letter is a capital and the mode word is lowercase: “C major”, “A minor”.
Continue on Maikstrings
Related terms
MajorA minorG majorF majorScaleDiatonic chordKeyRelative keyCircle of fifths
Editor: Maik Krohm · reviewed on 3 October 2026
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