All keen jazz players make sure that they explore their knowledge through all 12 keys. The reason for this is straightforward. Jazz is a complex music, and everything we play has reference and meaning throughout the 12-tone system. Unfamiliarity with any area of this system limits our ability to hear and improvise freely.

The question is, how best should we work through the keys? Some people go round in semitones, others in fourths; others go halfway round in tones, then shift by a semitone and then finish off the other half in tones. I like all these methods. But my favourite method is the one I show you in this chart. It groups the 12 tones in 4 sets of 3 related key centres. This relation, between keys a major third apart, is fundamental to much composition and improvisation, and so it makes sense to build it into our practice sessions.

This particular chart, just a series of ii-v-i progressions through the keys, is also useful for other reasons, as it embodies some important principles:

• We start on the 7th of the mi7, come down a semitone onto the 3rd of the dom7, and then play a melody up the parent scale to land on the third of the tonic chord.
• Within each set of three key centres, the 3rd of each major chord is the same note as the 7th of the mi7 on the following line.
• We push into bars 2 and 3, playing our target note for the chord on 4 and
• Our melody rises up to express the strong rhythmic and harmonic pull of the dom7 towards the tonic chord, as v moves to i. Make sure your quavers stay strong as the surge happens!

This is a great chart on its own, but if you use this arrangement of the tones to translate as well your own vocabulary all round the 12 keys, you will receive much benefit.