In most pop, rock and soul songwriting these more complex chords are not used very often. Fascinating as they are, try not to get carried away with them. It is a fatal habit among keyboard players who write songs that because it is easy for them to play extended chords they have to use them all the time. I have known keyboard players who seemed incapable of playing a simple C Em Am G progression without turning it into C11, Emadd9b5, Am7b5 and Gdom11 . This is as beside the point as guitarists who insist that every song has to have at least two long guitar solos! Of course this stuff is interesting to play. But song writing is not about giving yourself interesting things to play. The individual instrumental parts of a song may be rather dull, or at least not taxing, but the magic of the song is in the whole being greater than the sum of the parts.

So use extended chords carefully, just to add a touch of colour here and there. One ninth chord placed at a telling position in a chord progression can add far more than half a dozen. One way to try this out is to take some of the turnarounds in section 3 and change one of the chords into a more complicated form.

Now it is time to explore one of the most exciting areas of songwriting craft. Got your backpack, provisions,suncream and maps? We are going travelling into the world of key changes.