Major scales and key signatures

Most of the songs you know are in a major key. Every major scale is built from the same pattern of tones and semitones.

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The major scale pattern

A scale is a set of notes going up or down in order, from one note to the same note an octave higher.
The C major scale uses only white keys: C D E F G A B C.
Every major scale follows the same pattern of steps: tone, tone, semitone, tone, tone, tone, semitone (T T S T T T S).
The first note is the tonic (the home note). The 5th note is the dominant.

Other major keys

Start the pattern on a different note and you need sharps or flats to keep it correct.
KeyNotesKey signature
C majorC D E F G A B Cnone
G majorG A B C D E F# G1 sharp: F sharp
F majorF G A B flat C D E F1 flat: B flat
D majorD E F# G A B C# D2 sharps: F sharp and C sharp

Key signatures

Instead of writing a sharp or flat before every note, a key signature is written just after the clef at the start of each line. It tells you which notes are sharp or flat all the way through.
A piece in a key feels as if it is pulled back to its tonic. Music in a major key often sounds bright or happy, though composers can use major keys for many moods.
An arpeggio is the 1st, 3rd and 5th notes of the scale (and the top note) played one after another: C E G C in C major.
Worked example

Use the major scale pattern to show why G major needs an F sharp.

  1. Start on G and follow T T S T T T S.
  2. G to A (T), A to B (T), B to C (S), C to D (T), D to E (T).
  3. Next must be a tone above E: that is F sharp, not F. Then F sharp to G is a semitone, as the pattern needs.

Answer: The 7th step must be a tone above E, which is F sharp, so the final step to G is a semitone.

Key idea

Major scale pattern: T T S T T T S. C major has no sharps or flats; G major has F sharp; F major has B flat; D major has F sharp and C sharp. The tonic is the home note; the key signature shows the sharps or flats.

Key words
Key signatures
C major and A minor: none. G major and E minor: F sharp. F major and D minor: B flat. D major and B minor: F sharp, C sharp.
Major scale pattern
Tone, tone, semitone, tone, tone, tone, semitone (T T S T T T S).
Tonic
The first note of a scale: the home note of a key.
Key signature
The sharps or flats written after the clef, showing the key of the music.
Octave
The distance from one note to the next note with the same letter name, 12 semitones.
Tone
A step of two semitones.

All KS3 Music key terms and definitions →

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2 more questions

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  1. In a major scale, between which degrees are the semitones?

    1. 1 to 2 and 5 to 6
    2. 3 to 4 and 7 to 8
    3. 2 to 3 and 6 to 7
    4. 4 to 5 and 6 to 7
    Show the answer

    Answer: 3 to 4 and 7 to 8

    The pattern is T T S T T T S.

  2. Which sharps are in the key signature of D major?

    1. F sharp only
    2. C sharp and G sharp
    3. F sharp and C sharp
    4. No sharps
    Show the answer

    Answer: F sharp and C sharp

    D major has two sharps.

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Last updated 2 October 2026. Spotted a mistake? Tell us and we will fix it.

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