EVEN IF YOU’RE NOT MUSICAL you’ll have heard people pouring scorn on bands like Status Quo, who appear to know only three chords. But why those three chords? What’s special about them?

Let’s say you’re playing in the key of C. The scale of C can be played entirely on the white notes of a piano.

The two chords ‘nearest’ to C are G and F. That’s because the scale of G has just one sharp, which makes it similar in sound to C.

Equally close, in the other direction, is the scale of F. It has just the one flat.

The chord of C uses three notes: C, E and G, as we’ve seen here. The chord of G uses the notes G, B and D; and the chord of F uses the notes F, A and C. With those three chords you have every note of the scale of C covered, with a couple of duplicates that means some notes can be played with two different chords.