This is the first chapter I assign to keyboardists serving in churches who read traditional notation but don’t know how to improvise. It takes advantage of their reading skills. It teaches them how to refashion what is on the page by revoicing/respacing the sounds so that more dynamic contrast is achieved.
This file is 31 pages long and has 45 musical examples with a running commentary included of what is going on technically. It’s a serious attempt to help you start to make the transition from just reading traditional notation to doing basic improvisation. I think you will find it to be an effective first step.