Marc Johnson is another American double bassist but, unlike David Friesen, I only have one of his albums (The Sound of Summer Running). It is one of my favourite jazz albums of all time but that is not the reason I esteem him as an influence.

Instead it is because of a book he wrote about the art of jazz improvisation, which provides a methodical series of explanations and exercises looking at ways to develop melodic, rhythmic and harmonic concepts to create interesting improvisations.

I know I need to go back and study it some more but, while I don’t pretend to have mastered the book, it has certainly played its part in shaping my approach to jazz.