Key signatures and the circle of fifths in VCE Music
“The identification and construction of major and minor key signatures, the order of sharps and flats, the circle of fifths, and the use of relative and parallel keys in performed and studied repertoire”
A key signature is the group of sharps or flats written at the start of a stave that fixes which notes are altered throughout a piece. The circle of fifths arranges all twelve major and minor keys in order, each one a fifth from the next, so that neighbouring keys differ by exactly one sharp or flat. Knowing the order of sharps and flats and the circle lets you name any key at sight and move between related keys fluently.
What this dot point is asking
Key signatures are the shorthand that tells you what key a piece is in. In the aural and written examination you must name a key from its signature, write the correct signature for a given key, and recognise the relationships between keys that composers use when they change key. The circle of fifths is the single diagram that ties all of this together.
The order of sharps and flats
Sharps and flats are never added randomly. They appear in a fixed order.
The order of sharps is F, C, G, D, A, E, B. The order of flats is the exact reverse: B, E, A, D, G, C, F. A key signature always adds them in this order, so a signature with three sharps must be F sharp, C sharp and G sharp, never any other combination.
A common memory aid for sharps is the phrase Father Charles Goes Down And Ends Battle, and for flats the same words reversed, Battle Ends And Down Goes Charles' Father. Each successive key in the sharp direction adds the next sharp; each successive key in the flat direction adds the next flat.
Naming a major key from its signature
There are quick rules. For sharp keys, the last sharp is the leading note, so the tonic is one semitone above it: a signature ending in F sharp means the key is G major (F sharp is the leading note, G is the tonic). For flat keys, the second-to-last flat names the key: with B flat and E flat, the key is B flat major. The single exception worth memorising is F major, which has one flat (B flat).
The circle of fifths
The circle of fifths places C major at the top with no sharps or flats. Moving clockwise, each step up a perfect fifth adds one sharp: G, D, A, E, B. Moving anticlockwise, each step down a fifth adds one flat: F, B flat, E flat, A flat, D flat. At the bottom the sharp and flat keys meet as enharmonic equivalents, for example F sharp major and G flat major.
Neighbouring keys on the circle of fifths differ by only one sharp or flat, which is why composers most often change key to a near neighbour. A piece in C major most naturally moves to G major (one sharp, its dominant) or F major (one flat, its subdominant), because those keys share the most notes with the home key.
Relative and parallel keys
Two relationships matter constantly. Relative keys share the same key signature but have different tonics: every major key has a relative minor a minor third below it, so C major and A minor both have no sharps or flats. Parallel keys share the same tonic but different signatures: C major and C minor start on the same note but C minor has three flats. Spotting whether a passage in minor is the relative or the parallel of a nearby major key is a frequent analysis and aural task.
A piece has a key signature of three flats. The order of flats fixes them as B flat, E flat and A flat. For the major key, the second-to-last flat is E flat, so the major key is E flat major. Its relative minor lies a minor third below the major tonic, which is C minor, and C minor uses the same three-flat signature. So a three-flat signature means either E flat major or C minor, and you decide which by checking the tonic note and the harmony.
Telling major from minor
A key signature alone does not tell you whether the piece is major or its relative minor, because they share the signature. You decide from the music: look at the opening and closing notes and chords, and listen for the raised seventh (the leading note) that minor keys borrow through the harmonic minor. If the tune keeps returning to and ending on the relative minor tonic, and you hear a raised seventh, it is in the minor key.
A frequent error is naming a key from the number of accidentals without checking major against minor, so a student writes E flat major when the piece is actually in C minor. The signature gives you a pair of possible keys, never one. Always confirm the tonic from the opening and final chords and from the presence of a raised leading note before committing to major or minor.
Drill the order of sharps and flats until you can write any signature instantly, sketch the circle of fifths from memory, and practise naming both the major and relative minor for every signature. Secure key knowledge speeds up transcription, harmonic analysis and recognising modulations in studied works.
Exam-style questions
Questions in the style of VCAA exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
2025 VCAA-style2 marksAdd the appropriate clef and key signature to make the following scale A major.Show worked answer →
Two marks: one for the correct clef placed at the start of the stave, and one for the correct key signature.
A major has three sharps: F sharp, C sharp and G sharp. Using the circle of fifths, A is three steps clockwise from C (C, G, D, A), so it takes three sharps. The order of sharps is fixed - F, C, G, D, A, E, B - so the first three (F sharp, C sharp, G sharp) are written on their correct lines and spaces in the chosen clef.
Add the clef that suits the printed pitches (most commonly treble), then place the three sharps in the standard order and standard positions for that clef. Writing the sharps out of order, in the wrong octave position, or giving the wrong number (two or four) loses the key signature mark.
2023 VCAA-style3 marksAdd the appropriate clef and accidentals to make the following the D major scale.Show worked answer →
Three marks for producing a correct D major scale: the clef plus the accidentals that define the key.
D major has two sharps: F sharp and C sharp. On the circle of fifths D is two steps clockwise from C (C, G, D), so it takes two sharps, taken in order from the fixed sequence F, C, G, D, A, E, B.
Add the appropriate clef first, then raise every F to F sharp and every C to C sharp across the scale so the pattern of tones and semitones (tone, tone, semitone, tone, tone, tone, semitone) is correct from D to D. Forgetting either sharp turns the line into a mode rather than D major and loses marks.