Have you ever met a player who can seemingly play any song in any key, coming up with different chord substitutions on every chorus? If you have been playing for a while but thought this skill was something magical and beyond you, then this book is for you. What allows players to do these things is the ability to recognize and understand common chord progressions and to reproduce them by ear as easily as one can play melodies by ear. This is a skill that you too can learn! After mastering the concepts explained in this book, you will find you are able to play by ear, in any key, with appropriate chord changes, any standard you know well enough to hum. You will also be able to make a variety of different substitutions while playing, and you will also see improvements in your improvisation and composition abilities.