I’ve been teaching some year 5 classes about melody recently, helping them to realise that good melodies don’t just happen by accident. It’s not that composers slavishly follow rules to compose memorable tunes, because most of the time, a good melody does present itself as if my magic. But there are certain truths I suspect which composers unconsciously tap into when they write a melody which is going to be remembered.

The first truth is about space. Not space as in the cosmos. But space within the melody, both in its timings and in the gaps between consecutive notes. Let me show you by quoting a well known melody – Twinkle Twinkle Little Star:

Look at the first three notes. The tune is played CCG. That leap between the C and the G of the third note is called an interval of a fifth – a perfect fifth if you want to be precise. It is found in countless pieces of music, and it gives a suggestion of scale, of importance. It’s there too in the theme to Star Wars:

So it’s important to leave spaces between the notes – not to just run up and down the scale. These gaps are important. They speak of something. If we look at the theme to Star Wars, they speak of strength, of adventure, of reaching for the skies. Look at where the melody goes next after those first two notes in Star Wars. The melody comes down three steps, as if it’s finding ground again, but it’s only so that it can build up the energy to launch into space, with that high C.

But you’ll notice too that not all the notes look the same – some are coloured in black, others have white innards. this tells a musician how long the sounds are. If Star Wars had notes all the same length, it would be a very tedious tune. In fact it wouldn’t even make much sense as a tune. The rhythmic timings – the spaces between one note sounding and the next, are what make a tune really captivating. You need both spaces of pitch (up and down space between consecutive notes) and spaces of duration (the length of time between different notes sounding.)

Let’s have another look at how a good melody makes use of pitch – the intervals or spaces between the notes. Somewhere over the Rainbow is a beautiful example of a finely crafted melody which, like Star Wars, tells its story through the tune as much as through the lyrics.

That’s a tune with spaces! That first gap between first and second notes is what we call an octave – a whole eight notes stretch. The melody is made up of a number of small phrases which constantly find their way upward. The effect of this is to give a yearning sense to the music – portraying perfectly Dorothy’s desire to escape from her humdrum existence and find what she dreams for. But even though every individual phrase is always questing upward, the actual shape of the whole tune is inexorably downward. Look at each bar. The direction within each is upward. But after that first huge leap in the first two notes, everything is basically travelling downward pitch-wise, bringing it back to the note it starts on. The effect of this is to ground the tune, just as Dorothy, as she sings the song, is still bound to her life in Kansas. The adventure she dreams of is just that – a dream.

There is another truth in the world’s best melodies. It’s simply this – once you’ve got an idea, repeat it. If something is worth saying, it’s worth saying twice, or three times. Look at Twinkle Twinkle Little Star – I’ve colour coded the phrases so you can see the repetition.

So there are two areas of repetition – the first line in its entirety is repeated as the final line, and the middle line (yellow) is itself a two part carbon copy. Do you want to know why this tune is so easy for children to learn? It’s because of the repetition. Our brains like order. They like to feel comfortable. And if they hear a tune which is then repeated, they think, “Oh I know this – I’ve heard it before” And it becomes what we call a hook, or an earworm – it gets in the brain without even trying.

What about the other two tunes I’ve looked at? Star Wars has a repeating phrase (yellow box), but the entire first line is itself repeated as the second line (red box).

Is this because John Williams was feeling lazy? Not at all – he’s a master melody-creator who knows that to create the sense of rightness and order which the human brain craves we need repetition.

And let’s have a look at the third example. The repetition in “Somewhere over the Rainbow” is less obvious, but it’s there – in the shape of the phrases. There are two building blocks, if you like. The first, picked out in yellow, is the yearning upward leap. The red phrases are the same shape every time – the starting note of the phrase drops three notes and then finds it’s way back up stepwise.

Don’t get me wrong – there are many wonderful melodies out there which don’t always reflect these truths, these needs for space and for repetition. But I’d hazard a guess and say that actually, they probably do, but they might hide it a little better. The next time you’re listening to a good tune, see if you can hear what I’ve been talking about – see if you can hear those leaps and spaces, those longer sounds interspersed with shorter ones. Those examples of repetition. Because good melodies don’t just happen.