You might have heard that there are three chords which, if you learn them, you can play just about any song in the world. It’s true. So many songs only use three chords and many more can be boiled down to only three. The reason for this is that these chords form the main building blocks of our western scale. In any key, the chords are known as I, IV, and V (1, 4 and 5). They are the pillars that will hold up the structure of the music when everything else is stripped away.

It is customary to write harmony (chords) in roman numerals. This is handy as you don’t get it confused with any other number; you see a roman numeral in music and you know we’re talking about harmony.

Chord I is the home chord. The music needs to come here to sound finished, therefore most songs end on chord I. If you want your music to sound unresolved, finish on any chord apart from I.

Chord V is the next important, called the ‘dominant’ in classical terminology, pretty self-explanatory. There are properties in the dominant which lead compellingly to those of chord I, so V is the chord that most often takes us home. After chord V comes

Chord IV the ‘subdominant’ (the most dominant chord after the dominant).

This is how they are organised on the piano keyboard –

The key of C

The key of G

So you can find chords I, IV and V by counting up the notes. You may be able to just work it out aurally by finding thee chords that feel right in each key. I think it’s useful to be able to do both.

The three chord trick in every Key

A fantastic example of the three chord trick is ‘The Lion Sleeps Tonight’. The entire song uses the following chord sequence in a loop –

If you know the chord relationships (as in the table above) you can play it in every key. This song is the subject for my next blog. I will add downloadable charts for it in a few keys, some with the corresponding ukulele diagrams.

We have only been talking about major keys so far. Minor chords are notated by roman numerals in the lower case, so in the minor key they would look like this: i, iv, V. The three chords have the same functions in the minor keys, only the dominant stays major in order to use the leading properties mentioned above and take us back to chord I.

Many songs use the three major chords and one minor chord. This is most likely to be chord vi (6). It is the most common chord after the three chord trick. An example of this is ‘Heart and Soul’, that piano duet you always learn from friends at school –

All the songs in this brilliant video have this structure –