ABRSM Grade 5 Theory Intervals: Section 4, Step by Step

By Michael Q. Klein

Intervals are Section 4 of the ABRSM Grade 5 Theory exam: 10 questions, 1 mark each, 10 marks in total. They also turn up all over the rest of the paper: in transposition (2.3), in chords, and in the true/false statements of Music in Context (7.2). Get intervals secure and a lot of other questions get easier too. This guide is part of how to pass ABRSM Grade 5 Theory, which covers every section, the best study order and a six-week plan.

The three interval questions in the exam

What you see on screen:

• 4.1 Name the interval: two notes side by side in the treble or bass clef, often with accidentals and ledger lines. Four options, and they mix two ways of naming big intervals, e.g. "diminished 11th" next to "compound diminished 5th". Both styles are correct names, but they mean different intervals here (a compound 5th is a 12th, not an 11th), so you need to know both.
• 4.2 Interval type: two notes again, but you only choose the quality from five fixed options. Watch every accidental, and any key signature: they all count.
• 4.3 Write the interval: one note is given, and you place a second note higher to make a named interval such as "minor 9th" or "compound major 6th". You choose the line or space and add a sharp, flat, double sharp or double flat yourself.

Every one of these comes down to the same two steps: the number, then the quality.

Step 1: The number (count the letters)

The number of an interval is found by counting the letter names from the lower note to the upper one, both included. C up to G: C D E F G is five letters, so it's a 5th.

Two things trip people up:

• Start counting at 1, not 0. The note you start on is number 1. C to D is a 2nd, not a 1st.
• Accidentals never change the number. C to G♯ and C to G♭ are both 5ths, because the letters are still C to G. Accidentals only change the quality (step 3).

You can also see the number on the stave without counting:

• Odd numbers (3rd, 5th, 7th): line to line, or space to space.
• Even numbers (2nd, 4th, 6th): line to space, or space to line.

And when the two notes are stacked, each interval has a shape you can learn to spot:

• 2nd: side by side
• 3rd: belly to belly
• 4th: half a space in between
• 5th: one note would fit in between
• 6th: a 5th and half a space
• 7th: two notes would fit in between
• Octave: a 7th and half a space

Step 2: Compound intervals (bigger than an octave)

Anything wider than an octave is a compound interval. Keep counting letters past the octave: a 9th, 10th, 11th, 12th, 13th. Each one is a simple interval plus an octave, so add 7 to go one way and take 7 off to go back:

• 9th = compound 2nd
• 10th = compound 3rd
• 11th = compound 4th
• 12th = compound 5th
• 13th = compound 6th

The quality stays the same. C up to the E an octave and a third higher is a major 10th, which is also called a compound major 3rd.

To find the quality of a compound interval, take the octave off and work it out as the simple interval.

Step 3: The quality (major, minor, perfect, augmented, diminished)

Here's the method that always works: imagine the major scale that starts on the lower note.

• If the upper note is in that major scale, the interval is major (2nd, 3rd, 6th, 7th) or perfect (4th, 5th, octave).
• If it's one semitone smaller than major, it's minor.
• If it's one semitone smaller than minor or perfect, it's diminished.
• If it's one semitone bigger than major or perfect, it's augmented.

So there are two ladders, depending on the number:

• 2nds, 3rds, 6ths, 7ths: diminished ← minor ← major → augmented
• 4ths, 5ths, octaves: diminished ← perfect → augmented

Worked examples

E up to C. E F G A B C is six letters, so it's a 6th. The E major scale has C♯, not C. C is one semitone smaller than the major 6th, so it's a minor 6th.

F up to B. F G A B is a 4th. The F major scale has B♭. B is one semitone bigger than the perfect 4th, so it's an augmented 4th.

B up to F. B C D E F is a 5th. The B major scale has F♯. F is one semitone smaller than the perfect 5th, so it's a diminished 5th.

When the lower note has an accidental

Some lower notes have awkward major scales (D♯ major is full of double sharps). The shortcut is to cover up the accidentals, name the interval, then put them back:

• Raising the upper note makes the interval bigger; lowering it makes it smaller.
• Raising the lower note makes the interval smaller; lowering it makes it bigger.

D up to A is a perfect 5th. D♯ up to A♯: both notes raised, so it's still a perfect 5th. D♯ up to A: only the lower note raised, so it's one semitone smaller, a diminished 5th.

The intervals you'll meet at Grade 5, in semitones

If you'd like to check by counting semitones:

• minor 2nd: 1 · major 2nd: 2
• minor 3rd: 3 · major 3rd: 4
• perfect 4th: 5 · augmented 4th: 6
• diminished 5th: 6 · perfect 5th: 7
• minor 6th: 8 · major 6th: 9
• minor 7th: 10 · major 7th: 11
• perfect octave: 12

An augmented 4th and a diminished 5th sound the same (6 semitones), but they're spelled differently. The letters decide which one it is, so always count letters first.

Step 4: Writing an interval (question 4.3)

To write a note above a given one, work in the same order:

1. Place the letter by counting up the number of letters (the given note is 1).
2. Fix the quality with the major scale of the given note, then add the accidental that makes it minor, augmented or diminished.

Example: a minor 9th above E♭. A 9th above E is F, an octave and a step higher. The E♭ major scale has F, so E♭ to F is a major 9th. A minor 9th is one semitone smaller, so the answer is F♭, not E. E would be an octave (the wrong letter), even though E and F♭ sound the same.

Example: a compound major 6th above B♭. A 6th above B is G; compound means an octave higher. The B♭ major scale has G, so the answer is plain G.

The mistakes I see most

• Counting from 0. The first note is always 1.
• Spelling by sound. F♯ and G♭ sound the same, but the letter decides the number. A 9th above E♭ must be some kind of F.
• Forgetting the accidental on the lower note. Always start from the lower note's own major scale, or use the cover-up shortcut.
• Ignoring the key signature. If there is one, it applies to both notes.
• Mixing up the two naming styles. A compound 5th is a 12th, not an 11th. Take 7 off to check.

Where intervals turn up in the rest of the exam

• 2.3 Transposition (5 marks): every transposing instrument is an interval away from concert pitch. B♭ clarinet and trumpet: a major 2nd. A clarinet: a minor 3rd. Horn in F and cor anglais: a perfect 5th. Tenor saxophone: a major 9th.
• Section 5, Chords: every triad is built from 3rds.
• 7.2 Music in Context: true/false statements often ask about intervals between neighbouring notes in a real extract, such as the widest or smallest one.

So the time you put into intervals pays off well beyond Section 4's 10 marks. For how the marks add up across the whole paper, read the ABRSM Grade 5 Theory pass mark.

How to practise intervals

• Learn the method step by step in the Grade 5 Skill Builder: interval size, then quality, then augmented and diminished, accidentals, compound intervals and writing intervals, each with explanations and a test.
• Drill the exam question types in the Interval Trainer: name, type and build, with every mistake explained.
• Check it under exam conditions in a timed mock exam, marked out of 75.

For the full preparation route, read how to pass ABRSM Grade 5 Theory.