Grade Five Music Theory - Lesson 6: Scales

Updated for the July 2020 ABRSM syllabus changes. (Scales in all four clefs can be found here).

Scales

A scale is a series of notes going up (ascending) or down (descending). For Grade 5 Music Theory, you need to know about diatonic scales and chromatic scales.

Diatonic Scales

A diatonic scale has 7 notes and each of those notes is given different letter name, A-G.

There are 3 main types: major, minor harmonic, and minor melodic. (There is also another type of minor - "natural minor", but you won't be tested on this).

Diatonic scales are usually played and written in groups of 8 notes, so that they sound finished. The 8th note is the same as the 1st note, but an octave higher or lower.

So,

A, B, C, D, E, F, G#, A1 is a correct scale, but

A, B, C, D, E, F, Ab, A natural is not a correct scale, because the letter name A has been used twice: once as A flat and once as A natural. (Even though you might think that G# and Ab are the same note, they aren’t!)

We talk about diatonic scales as being in a certain key, for example, in "C Major". Most of the scales you will have played up to now will have been diatonic scales. They are the most common type of scale in Western classical music.

You need to know how to write all the major, minor harmonic and minor melodic scales, with up to 6 sharps or flats in the key signature. You are asked to write scales starting on the tonic, which is the technical name for the first note of the scale. 

Tones and Semitones

All diatonic scales have something in common; they have a defined pattern of tones (whole steps) and semitones (half steps).

Imagine a piano keyboard: two neighbouring keys (whatever colour) are semitones:

E to F is a semitone and B to C is a semitone. A to B flat is one too, and so is G to G sharp .

If you take two notes with one note between them, you’ll have found a tone:

C to D is a tone, as are E to F sharp , D to E and B flat to C. 

Major Scales

All major scales are made up with the following pattern, where T=tone and S=semitone:

T-T-S-T-T-T-S 

Here are two examples:

G Major

and F# Major

If you’ve ever wondered why we need notes like "E sharp" when "F" seems to be the same note, you’ll see that we need them in keys like F sharp major! (Remember, you can only use each letter name once per octave).

If you write a major scale with a key signature, there are no accidentals to add.

Minor Harmonic Scales

All minor harmonic scales have the following pattern, where 3S=three semitones:

T-S-T-T-S-3S-S

For example:

D Minor Harmonic

and F Minor Harmonic

Minor harmonic scales use the same notes on the way down.

If you write a harmonic scale with a key signature, you always have to add one accidental. This accidental must raise the 7th note by a semitone (half step).

In an ascending scale it is the 7th note, in a descending scale it is the 2nd. It could be a natural, sharp or double sharp sign, but is never a flat sign.

Here is F minor harmonic written with a key signature. 

Minor Melodic Scales

Minor melodic scales are a little more difficult, because they have one pattern on the way up and a different pattern on the way down: 

Minor melodic ascending: T-S-T-T-T-T-S

Minor melodic descending: T-T-S-T-T-S-T

For example, here is a scale of C Melodic Minor:

Notice that on the way up we have A natural and B natural, but on the way down we have A flat and B flat.

If you write an ascending melodic scale with a key signature, you always have to add two accidentals, (natural, sharp or double sharp signs), to the 6th and 7th notes. These accidentals must raise each note by a semitone (half step).

F minor melodic ascending, with 2 accidentals.

If you write a descending melodic scale with a key signature, there are no accidentals to add.

F minor melodic descending, with no accidentals.

Technical Names

We use “technical” names to talk about each note of the diatonic scale, instead of saying “first note”, “third note” and so on. You need to learn these technical names because there are often general knowledge questions about them in Grade 5 Theory! 

Technical names are worked out from ascending scales.

For example, in C major ascending, the second note we write is D, so D is the supertonic in C major.

If we write out the scale of C major descending, the second note we write is B. But B is not the supertonic. The supertonic is still D; B is the leading note, because it is the 7th note in the ascending scale. 

Chromatic Scales

A chromatic scale has 12 notes, and each step of the scale is a semitone, (see above for more about semitones). If you start on a C and play every available note until you arrive at the next C, you have played a chromatic scale. We don’t talk about chromatic scales as being in a particular key; we just talk about the note they start on - and they can start on any note.

Here is an ascending chromatic scale starting on C:

 

You need to be able to recognise and write chromatic scales, and might have to find a section of a chromatic scale within a piece of music, or write one out.

To find a section of a chromatic scale, look for a series of notes that are all one semitone apart.

How to Write Scales

First, read the instructions very carefully, and underline the keywords about whether the scale should be:

• ascending or descending
• major, minor harmonic or minor melodic,
• whether should use a key signature or not.

Next, pay attention to the clef! (All this may sound obvious, but many students lose points when writing scales simply because they mis-read the question!)

Here's an example question:

Using semibreves (whole notes), write one octave of the ascending G# harmonic minor scale. Do not use a key signature, but add any necessary accidentals.

First, write in eight notes, starting with the tonic and finishing on another tonic. You can write the accidental on to the tonics (top and bottom) but don't add any other accidentals yet. Make sure that you write only one note per letter name: one note on each line and space.

Next, using the pattern for ascending harmonic minor scales (T-S-T-T-S-3S-S), add the necessary accidentals. You can sketch a piano keyboard out if it helps.

For example, the first step is a tone (whole step), so we add a sharp to the A to get G#-A#. The next step is a semitone (half step), and A#-B is already a semitone, so there is nothing to add to the B. Continue for the rest of the scale.

Notice that we needed an F## (double sharp) on the 7th note. F## is an enharmonic equivalent of G natural, but G natural would not be correct here, since we already use the letter name G for the tonic note.

Here's another question.

Write one octave of the descending F minor harmonic scale using semibreves (whole notes). Use a key signature and add any other necessary accidentals.

This time, we need to add a key signature, so that is the first thing to put in. The key signature for F minor has four flats. (See Lesson 5 on Key Signatures).

Next, write out eight notes from F to F, using each letter name once. Look again at the scale direction before you start: this will be a descending scale.

Finally, add any necessary accidentals. When you use a key signature, you only ever need to add accidentals to

• a minor harmonic scale, or
• an ascending minor melodic scale.

This is F minor harmonic, so we need to raise the 7th degree of the scale by a semitone (half step). 

Remember that the 7th degree of the scale is based on the ascending scale, so it is the note E in this case (count up 7 notes from the bottom F). Next, look again at the key signature: does it affect this note? In this case, yes it does. The 7th degree of the scale is actually E flat. We need to raise this by a semitone, so it will become E natural. Put in the accidental, and the scale is finished.

Don't forget, an ascending melodic minor scale will need both the 6th and 7th degrees raising by a semitone.

Common Errors

If you’re learning an instrument, you’ve probably played all these scales already, but you might have learnt to play them without thinking about the actual notes, (your fingers do the thinking!)

In Grade 5 Theory, you might be asked to write any scale, ascending or descending, either with a key signature or using accidentals. Here are some common mistakes: make sure you don’t make them!

• Not noticing a bass clef.
• Not using a different letter name for each note.
• Not noticing whether the question asks for a key signature or accidentals.
• Writing accidentals/key signatures on the wrong space or line.
• Writing an ascending scale when the question asks for a descending one, and vice versa. (Remember “D” for “Down” and “Descending”).
• Writing a harmonic instead of a melodic scale, or vice versa.
• Using the wrong note value - usually you are asked to use semibreves (whole notes).
• Forgetting to add an accidental to the last note of a scale, if necessary. Remember, an accidental on the first note of the scale (e.g. Bb) will NOT affect the same note an octave higher!

 Scales in All Four Clefs

You may be asked to identify the correct clef of a scale. The correct clef might be treble, bass, alto or tenor.

Here are some facts about scales which might help you to find the answer quickly:

• The tonic (keynote) will never be E#, Fb, A#, B# or Cb.
• Only two scales combine both flats and sharps: they are D minor (harmonic, and ascending melodic) and G minor (harmonic, and ascending melodic). (There are no major scales which use both flats and sharps).
• All scales (major and minor) contain the following intervals above the tonic (keynote):

Tonic-supertonic = major 2nd
Tonic-subdominant = perfect 4th
Tonic-dominant = perfect 5th

• All minor scales have a minor 3rd above the tonic.
• All major scales have a major 3rd above the tonic.

(Intervals are covered in detail in the next chapter).

Here’s an example question.

Select the correct clef to form a minor scale:

In this scale, there is one sharp, and one flat. This means we can narrow it down to either D minor or G minor. If you know your scales well, you might quickly see that it must be D minor, because the flat and sharp in the scale are adjacent notes (Bb and C#, 6th and 7th degrees of the scale). In G minor (melodic) the flat and sharp and Bb and F#, which are the 3rd and 7th degrees of the scale.

If you are less confident about spotting scale shapes, you will need to use a bit of trial and error, to check which scale works. Try each clef in turn, using your knowledge of intervals above the tonic:

• With a treble clef, the tonic would be E, so this can’t be the right clef, because it must be D or G.
• With a bass clef, the first note would be G, but the third note would be B (natural), so it can’t be a minor scale in the bass clef.
• With an alto clef, the tonic would be F, so this can’t be the right clef.
• A process of elimination tells us that it must be tenor clef, but you can also check that in tenor clef the first note is D, the third is F (minor 3rd above tonic), the 4th is G (perfect 4th above tonic) and the 5th is A (perfect 5th above tonic).

Here’s another example. Which clef will make this into a minor scale?

This time there are only sharps, and it’s a descending scale, so we can’t narrow it down so easily as in the previous example.

The best way to begin is by working out the tonic for each clef, then looking at the intervals above the tonic. As this is a descending scale, we need to work backwards, from the lower tonic.

• In the treble clef, the lowest note (tonic) is F#.
  → Minor 3rd above tonic ✓ (A)
  → Perfect 4th above tonic X (B#)
  → Cannot be treble clef
  
  
• In the bass clef, the tonic is A#.
  → A# isn’t used as a tonic, so cannot be bass clef
  
  
• In the alto clef, the tonic is G#.
  → Minor 3rd above tonic ✓ (B)
  → Perfect 4th above tonic ✓ (C#)
  → Perfect 5th above tonic ✓ (D#)
  → Seems correct, but let’s check tenor clef too.
  
  
• In the tenor clef, the tonic is E#.
  → E# isn’t used as a tonic, so cannot be tenor clef.

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