minor scale: three forms and the seven notes in each

Three forms, counted in semitones

All three forms keep the minor third above the tonic — that interval is what makes them minor — and they differ in the sixth and seventh degrees. Written as semitones between the eight notes of the octave, the natural form is 2, 1, 2, 2, 1, 2, 2; the harmonic form is 2, 1, 2, 2, 1, 3, 1; the melodic form going up is 2, 1, 2, 2, 2, 2, 1.

Harmonic minor changes one pair of steps: the last two steps, 2 and 2, become 3 and 1, so 2 · 1 · 2 · 2 · 1 · 2 · 2 turns into 2 · 1 · 2 · 2 · 1 · 3 · 1. That is the seventh degree raised one semitone: the step up to it grows from 2 to 3 and the step out of it shrinks from 2 to 1, so the pair still adds to 4 and the octave still adds to 12. Melodic minor raises the sixth as well, so the last three steps become 2 · 2 · 1 on the way up; 2 + 1 + 2 + 2 + 2 + 2 + 1 = 12 as well. Coming down, the natural form is used, which is why the descending row is the natural row read backwards.

A minor, all three forms, and the frequency of each note

A minor has no sharps and no flats in its signature, so its natural form is the white keys from A to A. The raised notes of the other two forms are written as accidentals — G♯ in the harmonic form, F♯ and G♯ in the melodic form on the way up.

Equal temperament with A4 = 440 Hz puts a pitch at 440 × 2^{((midi − 69) ÷ 12)} Hz, where midi is the note’s number on the MIDI scale. The natural form from A4 to A5, each note on its own line:

A5 is 2 × 440 = 880.00 Hz, an octave above A4. The raised notes of the other two forms have their own numbers on the same formula: G♯5 is midi 80, 440 × 2^{11 ÷ 12} = 830.61 Hz, and F♯5 is midi 78, 440 × 2^{9 ÷ 12} = 739.99 Hz.

C minor, all three forms

C minor’s signature carries three flats — B♭, E♭ and A♭ — so its raised notes are printed with natural signs, which cancel the flat for that one note. That is the whole difference between the three rows below: the three flats stay at the start of the line.

The three flats of the signature are spelled out, with the staff positions, on the three flats page; the same signature is E♭ major, which is where the relative major below comes from.

The relative major of each key

A minor and C major use the same seven notes, so a page with no sharps or flats can be in either; the note the music settles on decides. C minor and E♭ major share the three flats. The relative major sits three semitones above the minor tonic — A up three semitones is C, and C up three semitones is E♭ — which is why the two keys of one signature are a third apart rather than a second.

Those two pairs are the correspondence this page needs. How every key pairs with its relative minor is the job of its own page, and the count of signs for each signature is on the key signature chart.

When the key finder says a minor key, read the row

The key finder answers with a key name, a Camelot code and a confidence. When it says C minor, the seven notes are C, D, E♭, F, G, A♭, B♭ and the code is 5A; when it says A minor the seven are A, B, C, D, E, F, G and the code is 8A. Those are natural minor rows, because a detector hears a tonal centre and cannot tell which form a performer will play — the harmonic and melodic forms are choices written into a score.

The Camelot scale page lists 12A as D♭ minor (C♯ minor) and adds that the wheel page labels the same pitches D-flat minor; the notes column here uses the C♯ spelling. B minor, with two sharps, has its own page on the two sharps page.

A recorded example you can check

The key has two separate sources. The engraved score prints three flats — B♭, E♭ and A♭ — at the start of both staves, and heads the piece “Praeludium 2 / BWV 847”. The Wikipedia article The Well-Tempered Clavier, read on 23 October 2026, lists “No. 2: Prelude and Fugue in C minor, BWV 847” in its Book 1 table. Three flats read off a staff and a catalogue entry in an encyclopaedia are different documents, and they agree.

On 23 October 2026 at 05:30 EDT this site’s key finder read this 24-second clip as C minor, Camelot 5A, at 57% confidence, and labelled the reading low. It listed F minor (Camelot 4A, 14%) and E♭ major (Camelot 5B, 7%) next, and its on-screen note says F minor also fits and that the melody or chords should be checked before mixing. That percentage is the finder’s estimate for this file, not a measured accuracy rate. The printed signature and the reading agree, and the second key it offers, E♭ major, is the relative major of C minor — the one key that shares all three flats.

A second count from the audio alone puts 68.4% of the energy in the seven pitch classes of C natural minor, and the rest on notes outside the signature — F♯ at 14.4% and E♮ at 13.5% are the two largest. A count of this kind can say which notes are sounding; it cannot say which of them is home, and it cannot tell a written accidental from the spill of a neighbouring partial.

Minor scale: quick answers

What this page leaves open

• Three forms only. The jazz melodic minor, the modes of the minor scale, and the chromatic and pentatonic scales are other pages.
• The frequencies are equal temperament at A4 = 440 Hz.
• 57% is the finder’s estimate for this 24-second file, not an accuracy rate.
• The twelve rows are natural minor. A piece in C minor can use B♮ and A♮ without leaving the key.
• How every key pairs with its relative major is the relative minor page, not this one.