THOSE UNFAMILIAR WITH WRITTEN MUSIC tend to regard scores as an impenetrable mass of dots and lines. But it’s really quite straightforward: it’s just a graph of time (on the horizontal axis) against pitch (on the vertical axis).

Here’s how the beginning of the main tune from Handel’s Hallelujah Chorus would look if written out as a plain graph. The longer the horizontal line, the longer the note:

The trouble is, it’s all rather difficult to read. It would be a lot easier if we could get away with half as many horizontal lines, so we can make the notes twice as thick. Each note could then either be between two lines, or centred on a line. Something like this:

Let’s get rid of all those vertical lines, since they just get in the way. And we can make the horizontal bars narrower, with little spaces between them, to make it easier to read:

Better, but not there yet. There are still too many horizontal lines. So let’s use just five lines, and we’ll agree that the bottom line is E, and the top one is F. We’ll add a treble clef symbol to indicate this – it’s actually a stylised letter G, drawn around the G line second from bottom:

But we don’t know where the emphasis should come. So written music is broken up into bars, and when it’s played there’s a stress at the beginning of each bar – the first note of the bar is played louder than the rest. Because this piece of music naturally breaks into four beats per bar, let’s add the number 4 so that the musician knows how to read it:

This is, more or less, how written music started. But how are we to know exactly how long each note should be? We can see that the first note is longer than the second, but that’s not very accurate.  So rather than making each note longer, let’s use a code instead.

We can say that a filled dot with a vertical line attached represents one beat (a crotchet), and a dot with a tail represents half a beat (a quaver). We use a hollow dot to represent two beats (a minim), a hollow dot with no tail to represent four beats (a breve), and a short line for silence (a rest).

But hang on – there’s a problem on the first note. It lasts for three beats. How do we show that? One method is to use a tie, to link a minim and a crotchet together. And the extra 4 means four crotchets in a bar (as opposed to, say, four quavers, which would be 4/8):

To make things simpler, we use a couple more conventions. Rather than tying two notes together, we can place a dot after a note to indicate that it’s 50% longer than its stated length. And we can tie those quavers together, to show that between them they take up the length of a standard crotchet:

And that, in essence, is how music came to be written the way it is. Think of it as a graph, and you won’t go far wrong.