Work out your intervals like a Pro! (Part 2)
Welcome to part 2 of our blog series on how to work out intervals in your ABRSM online music theory exams. In this blog post, you’ll learn the more complex interval types that are found in Grades 3, 4 and 5 exams, and how to recognise them.
Please be aware that none of the methods we’re about to discuss works fully on its own, unless you are identifying very simple intervals. You have to use a combination of these methods to identify intervals in your ABRSM online theory exams fully, so make sure you learn all of them!
Interval types
From your ABRSM online theory exams from Grade 3 onward, you will need to know not just the number (2nd, 3rd, 4th etc.) of an interval, but also its type. With the different types of interval, the number stays the same, but the accidental (the flat, sharp or natural that goes with the note) will change:
At Grade 3, you will only need to know the minor and major interval types, but at Grades 4 and 5, two more types (the diminished and augmented intervals) are added.
Notice that because the number stays the same, the letters of the notes also stay the same. Compare these two intervals:
These two intervals actually sound the same, but because they don’t look the same, they are different intervals. You can also check this using a method from part 1 where we looked whether your interval goes from a line to a space, or a line to a line. Because one of your intervals (the 2nd) goes from a line to a space, and the other (the 3rd) goes from a line to a line, this further proves that these two intervals are different, even though they sound the same.
Intervals from scales
Scales are created from intervals as we write notes from left to right one at a time, either from low to high for ascending scales or from high to low for descending ones.
In ABRSM online theory exams for Grades 1 and 2, you only need to know the number of an interval, not its type, so this method is one of the easiest ways to identify intervals (along with the previous method we discussed).
Major scales
For example, let’s take the C major scale and work out all its intervals:
You can see that apart from the perfect intervals, which have the numbers 4th, 5th and 8th (or 8ve) every other numbered interval in a major scale is a major interval. Minor scales are a bit more complicated, because there are three different ways minor scales can be set up.
Minor scales
There are three different types of minor scales you’ll need to know for your ABRSM online music theory exams, and each one has its own set of intervals. First, we have the natural minor scale, which is the minor scale we get if we follow the key signature exactly, with no changes (no accidentals). Let’s look at the A minor scale, for example:
The next type of minor scale you’ll need to know for your ABRSM online music theory exams is the harmonic minor scale, which we can get from the natural minor scale by taking the seventh note and moving it up by one semitone:
The final type of minor scale you’ll need to know for your ABRSM online music theory exams is the melodic minor scale. This one can also be formed from the natural minor scale, but it is a little bit more complicated than the others because you have to be careful which direction you’re going in! On the way up, you have to move both the sixth and seventh notes of the scale up one semitone, but on the way down, those two notes come back down one semitone, to the same notes that they were in the natural minor scale:
Remember, on the way up, the 6th and 7th notes go up, and on the way down, they come back down.
Because the sixth and seventh notes of the minor scale can change, this gives us two possible intervals for the sixth and seventh notes, depending on the scale those notes come from. The intervals of a sixth or seventh can be either minor or major, and both are theoretically correct, but you have to be very careful to read the notes in your questions correctly!
Here is the complete set of intervals you can expect to see in a minor key (with the A minor scale as our example).
These intervals are taken from all of the minor scales (natural, harmonic and melodic):
Intervals by semitones
From your ABRSM online theory exams from Grade 3 onward, you will need to know this method of working out intervals. Unfortunately, there isn’t an easy way of learning all of these except by memorising them, but there are patterns here that can help aid your memory.
We looked at semitones and tones in part 1 of our series on intervals. Semitones are chromatic steps (from the Greek word chroma, meaning “colour”) and when we use them, it makes music more interesting because we are not just using only diatonic notes, or pure scale notes.
There are twelve semitones in one octave of a piano keyboard (from one note to the next note up or down of that same letter). Each distance has its own name, and you can learn them below:
1 semitone = minor second (minor 2nd)
2 semitones = major second (major 2nd)
3 semitones = minor third (minor 3rd)
4 semitones = major third (major 3rd)
5 semitones = perfect fourth (perfect 4th)
6 semitones = augmented fourth (augmented 4th) / diminished fifth (diminished 5th) – depending on how the note is written
7 semitones = perfect fifth (perfect 5th)
8 semitones = minor sixth (minor 6th)
9 semitones = major sixth (major 6th)
10 semitones = minor seventh (minor 7th)
11 semitones = major seventh (major 7th)
12 semitones = perfect octave (perfect 8th or perfect 8ve)
First of all, don’t get caught in the trap of thinking that the number of semitones in an interval equals the number of the interval itself! It doesn’t! In fact, there is only one interval (major 2nd) where this is true!
Also, notice how every minor interval is followed by a major one. Minor and major go together like heads and tails on a coin. If one type exists for a particular number, the other one also has to exist.
Imperfect and perfect intervals
Perfect intervals are the intervals with the numbers 1, 4, 5, or 8 (so they would be 1st, 4th, 5th or 8th/8ve – short for octave). The opposite of perfect intervals are imperfect intervals and these would be the other numbers that we haven’t used yet (so they would be the 2nd, 3rd, 6th and 7th).
Perfect intervals cannot be major or minor, but imperfect intervals can.
The interval lines
From Grade 4 onward, you may need to know the interval lines. These will help you to adjust intervals from the scales in order to find the types of intervals that cannot be found in scales.
You may remember working with number lines when you were first learning to count. Intervals work in a similar way. There are two lines you need to memorise for your ABRSM music theory exams:
Using these interval lines, you can see the progression from a diminished to an augmented interval when dealing with either imperfect intervals or perfect intervals. This is also a visual way of illustrating the difference between perfect and imperfect intervals.
Compound intervals
If you understand everything that has been discussed up to this point, compound intervals will be easy to understand.
Compound intervals are intervals that are larger than one octave. Let’s have a look at the D major scale now, but over two octaves instead of one, and counting each note as we go:
Notice that when we finish our first octave (in other words, our first eight scale notes, which end with the D), every other note after that keeps counting up normally past the number 8. So the next E would be 9, the F♯ would be 10, and so on until the second octave finishes with the final D, which is note number 15.
These numbers are the ones we use to indicate compound intervals. Also, there is a pattern here. If you look at the number of the scale note in the bottom octave, and then look at the same note in the top octave, the bigger number will be the smaller number plus 7. For example, the first E has the number 2, so the second one has the number 9. The first E is a major 2nd above the first note of the scale, and the second E is a major 9th above it.
You can also refer to the bigger numbered intervals using their smaller numbers by putting the word “compound” before the smaller interval. It is important to remember that you can’t use the word “compound” with the bigger numbers! So, for our example above using the E notes, you could either call the E in the second octave the “major 9th” or the “compound major 2nd”, but you should never call it a “compound major 9th”! You have to be aware of this, because in your ABRSM online theory exams, the questions will try to trick you using wrong ways of describing the intervals, so you have to know the right ones!
Well, that’s it for now on the subject of intervals. We hope this two-part blog series has been useful in helping you identify all types of intervals for your ABRSM online music theory exams. Remember to use all of the methods in both parts of the series if you want to be absolutely sure you get your answers correct in your ABRSM online music theory exams!
Please get in touch with us by commenting below if you have any further questions you’d like us to answer, or things you’d like us to talk about in our future blogs! 😄
See you next time!
🎵Ashbea Music 🎵
P.S. If you need any more resources for learning how to recognise and practice intervals, here are some links to products that we use in our online music theory lessons with our students!
