Relative vs parallel keys: compare tonic and key signature

“These keys are related” does not tell you what stays the same. Write two questions: Do they have the same tonic? and Do they have the same key signature? Keep the words “major” and “minor” beside each tonic so the label is complete.

Parallel major and minor share the tonic. Relative major and minor share the signature. Source: Open Music Theory, parallel and relative relationships. For this guide, a minor key’s signature uses its natural-minor collection; the changing notes of harmonic and melodic minor are a separate construction task.

Use the major-signature guide first if signatures are unfamiliar. The aim here is to explain a relationship between two named keys, not infer the key of a recording from its mood or give every scale another name.

Read the first two rows aloud in full: “C major and A minor are relative because their signatures agree, while their tonics differ.” “C major and C minor are parallel because their tonic agrees, while their signatures differ.” The reason is part of the answer.

The final row matters: two keys are not automatically relative just because one is major and the other minor. “Neither” here only rejects the two relationships under study; it does not claim that musicians cannot connect those keys in a composition.

To find the relative minor from a major scale you know, use its sixth degree. For the reverse direction, use the third degree of the natural-minor scale. You can also check that the minor tonic is a minor third below the major tonic; counting semitones alone still requires the correct written letter. Source: Music Theory for the 21st-Century Classroom, minor key signatures.

Try our E-flat-major example: E♭ F G A♭ B♭ C D E♭. Its sixth degree is C, so test C minor. Both signatures contain B♭, E♭ and A♭. C minor’s natural scale begins C D E♭, and its third degree returns you to E♭ major.

Now use G-flat major: G♭ A♭ B♭ C♭ D♭ E♭ F G♭. Its relative minor is E-flat minor. Calling it D-sharp minor may reach an equivalent piano-key tonic in equal temperament, but it does not preserve the signature’s spelling. E-flat minor uses six flats, while D-sharp minor uses six sharps. Write the key relationship, not merely a matching keyboard sound.

For a parallel key, no tonic calculation is needed. The parallel minor of E-flat major is E-flat minor. The tonic remains E-flat, though its major and minor signatures differ. Do not replace it with C minor merely because you just calculated the relative.

A signature alone does not establish a piece’s tonal centre. In a major/minor exercise, the same signature gives a major candidate and its relative minor; real music also requires context. Source: Open Music Theory, “Major or Minor?”.

Suppose a worksheet shows one sharp and asks only for its major key. “G major” answers that limited question. Suppose instead a score shows one sharp and asks for the key of the music. “G major or E minor are initial candidates” is a better first note; inspect how phrases and harmonies establish a centre before deciding. A first note, last note or isolated accidental is a clue to examine, not a universal proof.

Our sorting exercise supplies the complete key names, so it does not ask you to perform that larger analysis. Keeping the input explicit lets you practise relationships without inventing evidence about an unheard piece.

Mark each pair relative, parallel or neither. Add the shared property, or state that neither tonic nor signature agrees.

1. F major / D minor.
2. A major / A minor.
3. D major / B minor.
4. B♭ major / G minor.
5. C major / E minor.

Open the reasoned answers

1. Relative: both have B♭; tonics F and D differ.
2. Parallel: tonic A; A major has F♯ C♯ G♯, A minor no sharps or flats.
3. Relative: both have F♯ C♯; tonics D and B differ.
4. Relative: both have B♭ E♭; tonics B♭ and G differ.
5. Neither: C and E differ; C major has no sharps or flats, E minor has F♯.

Download the relative-and-parallel worksheet (plain text). Its final prompt asks you to give both the relative minor and parallel minor of one major key. If your two answers are identical, return to the two column headings and explain which property each answer must preserve.