Ear Training: Two Note Complete is the next level up from the "Ear Training: One Note" Series. It is recommended to master the One Note Series and "Key Note Recognition" before attempting this book. This method for developing relative pitch ear training and key modulation recognition has been used with great success and through the series of books and separately available CDs one can obtain outstanding pitch recognition abilities. There are six CDs that can be purchased separately for this book. Through practice, the student eventually gains the ability to recognize the key and the names of any two notes played simultaneously. Each of the six separately available CDs concentate on a different two note combination.