Writing Chromatic Scales: The Ultimate Guide

By Michael Q. Klein

Here is everything you need to know to pass the chromatic scale questions in the ABRSM Grade 5 Theory exam (section 3.6 a and b, where you decide whether a chromatic scale is written correctly). It boils down to four rules. A correctly written chromatic scale must:

1. Contain every chromatic step — all twelve pitches of the octave, one semitone at a time.
2. Have at least one note on every line and space.
3. Have no more than two notes in a row on the same line or space.
4. Have no two notes that are enharmonic equivalents of each other.

That's it. These rules come from ABRSM's own textbook, Discovering Music Theory: Grade 4 (page 34).

The four rules, explained

Rule 1: every chromatic step

A chromatic scale moves in semitones from a note to the same note an octave higher (or lower). That means twelve steps and thirteen notes, and every one of the twelve pitches in the octave appears exactly once (plus the key note again at the end). If a step is missing — say the scale jumps a whole tone from C to D — the scale is wrong. The quickest first check in the exam: count the notes. If there are not thirteen, it's false.

Rule 2: every line and space has a note

Read up (or down) the stave from the first note to the last. Every line and every space in between must be used by at least one note. In other words, all seven letter names have to appear. A scale that goes E, E♯, G♭ is wrong even though the pitches are right, because the F space has been jumped over.

Rule 3: no more than two notes on the same line or space in a row

Each line or space can hold one or two notes, but never three in succession. A♭ – A♮ – A♯ is always wrong: three notes in a row on the A space.

Rule 4: no enharmonic equivalents

Enharmonic equivalents are the same pitch written in two different ways, like A♯ and B♭, or C and B♯. A chromatic scale may never contain both spellings of one pitch. In practice, the place this catches people is the last note: it is the same pitch as the first note, so it must be written the same way. A scale that starts on C must end on C — not on B♯.

Notice what is not in the list: there is no rule about using sharps going up and flats going down, and no rule about which key the scale belongs to. You can mix sharps and flats freely. As long as all four rules hold, the scale is correct.

Two correct examples

A ascending (treble clef)

Thirteen notes, each a semitone apart, so every chromatic step is there (rule 1). Every line and space from A up to A has a note: A, B, C, D, E, F, G, A (rule 2). No line or space has more than two notes in a row (rule 3). There are no enharmonic pairs, and the scale starts and ends on A (rule 4). Correct.

E♭ descending (treble clef)

This one mixes naturals and flats, and that is fine. Thirteen notes in semitones (rule 1), every letter from E down to E is used (rule 2), never more than two in a row on one line or space (rule 3), and no pitch is spelled twice; it starts and ends on E♭ (rule 4). Correct.

Four incorrect examples (one for each rule)

Breaking rule 1: a missing step

Count the notes: only twelve. The scale jumps a whole tone from C to D, so C♯ is missing.

Fix: add C♯ between C and D.

Breaking rule 2: an empty line or space

The pitches are all correct and in order, but look at the letter names: G, G♯, A, A♯, B, B♯, D♭, D… there is no C. The C space is empty.

Fix: change B♯ to C.

Breaking rule 3: three notes on the same line or space

A♭, A♮ and A♯ are three notes in a row in the A space.

Fix: change A♭ to G♯. Now G and G♯ share the G line, and A and A♯ share the A space.

Breaking rule 4: an enharmonic equivalent

The scale starts on B♭ but ends on A♯ — the same pitch written a different way.

Fix: change the last note to B♭, to match the first.

What you actually do in the exam

In the exam you don't need to write chromatic scales, and you don't need to fix them. You only need to check the four rules:

1. Every chromatic step is there.
2. Every line and space has at least one note.
3. No line or space has more than two notes in a row.
4. No two notes are enharmonic equivalents.

If at least one of them is broken, the scale is wrong. Otherwise, it is correct.

Is it really that simple?

Yes. It used to be more complicated. If you are interested in the old rules — which are still valid principles for how to write chromatic scales — you can read on below. But if you just want to pass the exam, what you should do next is work through examples until checking the four rules is automatic.

On Play Music From Within the Grade 5 suite has a dedicated trainer for chromatic scales alongside every other exam subsection, with unlimited generated questions in all four clefs and a worked explanation after each one, telling you exactly which rule a wrong scale breaks. It also tracks your accuracy per subsection, so you can see whether 3.6 is genuinely secure or just occasionally lucky.

When you want the real thing instead of a drill: Sign in to take your free full mock exam — a complete paper in exam order with explanations as you go. Prefer it under pressure? Sit a timed session that scores you at the end like the live exam. To see everything the ABRSM Grade 5 theory mock exams include, and which plan suits students, parents and teachers, start at the overview.

Not sure where you stand yet? The free readiness check takes a few minutes and gives you a personalised practice plan, so you train the weak sections instead of the comfortable ones.

The old rules: harmonic and melodic chromatic scales

For a long time, theory books — including ABRSM's own The AB Guide to Music Theory (the "pink book") — taught two specific ways of writing chromatic scales: the harmonic and the melodic chromatic scale. Both still follow the four rules, so both are still correct. They are just no longer the only correct spellings. Here is what the book says about each, worked through with examples.

The harmonic chromatic scale

The section of the book dealing with chromatic scales (pg. 30 ff) is about 2 1/3 pages long, but spends the first 1 1/3 pages illustrating that composers don't really care about the writing rules. Then there is only about 1 page going very briefly through the rules, without much explanation or examples. The part with the actual rules starts like this: "Theorists distinguish between two ways of writing the chromatic scale: the harmonic and the melodic. The harmonic chromatic scale is the same whether ascending or descending, or whether it occurs in a major or in a minor key. It includes all the notes of the major and minor scales (both harmonic and melodic), plus the flattened second and the sharpened 4th degrees. In practice this always means every degree of the scale has to be written twice except the 5th and, of course, the key note at the top and bottom. e.g."

D major

D minor

This is where the section on harmonic chromatic scales ends in the book. So what does this mean? It means that apart from the scale being the same whether it's ascending or descending, it's also the same irrespective of what the key is. In short, every ascending harmonic chromatic scale uses: the tonic, minor 2nd, major 2nd, minor 3rd, major 3rd, perfect 4th, augmented 4th, perfect 5th, minor 6th, major 6th, minor 7th, major 7th, and the tonic again at the top.

In the ABRSM exam there are no key signatures written, so in the examples below I won't use any either. The key note is determined by the first and last note. Major or minor does not matter, because it's the same notes for both. Let's do C as the tonic, both ascending and descending.

C ascending

C descending

On C this is pretty straightforward. Now let's look at a key note that is itself a flat: G♭. This is where it gets weird.

G♭ ascending

G♭ descending

G♭ is the tonic, but then I need a minor second. This can't be G — that would be an augmented unison. It needs to be some kind of A, so to be a semitone, it needs to be A double flat. The same logic gives B double flat (minor 3rd) and E double flat (minor 6th).

The melodic chromatic scale

Let's go back to the book for this one: "Melodic chromatic scales are less rigid in their construction: in fact theorists do not invariably agree how they are formed. What may be said is that they differ in their ascending and descending versions, and also according to whether the key is major or minor. Perhaps the simplest way of forming them is to include, first, all the notes of the key (in a minor key these include the notes of both the melodic and the harmonic scales). The additional notes are then provided by sharpening the diatonic notes (when required) in the ascending form, or by flattening them in the descending form."

D major ascending

D major descending

D minor ascending

D minor descending

"Some authorities, however, would always use the 7th degree twice (e.g. C♮ not B♯) in the ascending scale of D major; and some would include the sharpened 4th rather than the flattened 5th (G♯ rather than A♭) in both descending scales. One principle that all would accept is that the same letter must never be used more than twice in succession: thus A♭ – A♮ – A♯ would always be wrong."

OK, let's work through C major. First build the scale as instructed, starting with the notes of the major scale ascending and descending.

C major ascending — scale notes only

C major descending — scale notes only

Then we fill in the missing chromatic notes: sharps in the ascending form and flats in the descending form.

C major ascending — complete

C major descending — complete

Now C minor. Same method — the notes of the minor key (both harmonic and melodic) first, then fill the gaps with sharps ascending and flats descending.

C minor ascending — scale notes only

C minor descending — scale notes only

C minor ascending — complete

C minor descending — complete

Finally, a tricky one: D♯ minor, which needs a double sharp. Notes of the key first:

D♯ minor ascending — scale notes only

D♯ minor descending — scale notes only

Then fill the gaps: raise the note below on the way up, lower the note above on the way down. Where raising would need a double sharp, the next letter is used instead — E rather than D double sharp.

D♯ minor ascending — complete

D♯ minor descending — complete

Check any of these against the four rules and they pass — which is exactly why you no longer need to memorise the recipes.

Keep going: What's in the ABRSM Grade 5 Theory Exam? maps every section of the paper, and how to pass Grade 5 music theory is the full preparation route.