Grade One Music Theory - Lesson 13: Intervals

Melodic and Harmonic Intervals

We can measure the distance between two notes which are played together at the same time, like these:

The distance between these notes is called a "harmonic" interval.

Or we can measure two notes which are played separately, like these:

The distance between these notes is called a "melodic" interval.

We use the same method to measure both kinds of interval.

Measuring Intervals

When we measure an interval, we always start counting from the lower note. We then count upwards to the higher note.

Here, we start counting on the lower note, which is C. We count upwards to the higher note, E. This gives us C, D and E. We counted three notes, so this interval is called a third.

If we count four notes, the interval is a fourth, and so on, until we reach eight. If we count eight notes the interval is called an "octave".

In Grade One Music Theory, all the intervals you have to calculate will start on the tonic (1st note) of the scale.

Intervals in Different Keys

In Grade One Music Theory, you need to know about intervals in C major, G major, D major and F major. The method for working out intervals is always the same, no matter what the key is. However, don't forget that in G major you need F sharp, in D major you need F sharp and C sharp, and in F major you need B flat.

For example, in D major, an interval of a third will be this:

We start counting on the lower note, D. We count D, E and F sharp - three notes, so the interval is a third.

In F major, an interval of a fourth will have a B flat:

We count F, G, A and B flat - four notes, so it's a fourth.

Writing Intervals

There are two important steps to follow when you write intervals in your music theory exam.

First, you need to work out which notes you have to write, and secondly you need to write the notes clearly and accurately.

If you have to write an interval, you will be given the first (lower) note of the two, and you will be told what interval to calculate; something like this:

You'll also be told if you have to write a harmonic, or melodic interval. This one is a melodic interval, so we'll write the second note after the given note.

Remember that we start counting on the lower note, which is F in our example. We've been told to write a 7th, so we count seven notes upwards: F, G, A, B flat, C, D, E. The seventh note is E, so that's the note we need to write.

Don't forget that we were told to write a melodic interval, so in this case we will write the E after the F, and not directly above it:

Don't forget to look carefully at the clefs - you will normally have about 3 questions with the treble clef, and 3 with the bass.

One interval is a bit more awkward to write than the others, and that is the harmonic 2nd. Harmonic intervals are written directly above the given note, but the 2nd is too close to write directly, so we have to move it to the side a little. If you try to write it directly above, you will produce something unreadable like this:

We move the higher note to the right, but keep it close enough to the lower note that they are just touching:

Perfect!