Jean
I�m not so sure that you find the "secrets" of jazz or blues in a book. I�ve played a lot of jazz and blues in my life, but most on guitar or Hammond organ. If you don�t have the "feeling" inside, you will never find the right chords. There�s one thing to read something in the book and another to find out how you can use it when playing. But the only way is to practise and practise all over.
Good luck
Lindoz