Mark Greathouse has a master’s degree from Stanford University and has composed more than seventy piano compositions, some of which are used in this book. He and his wife, Helena, a former internat...view moreMark Greathouse has a master’s degree from Stanford University and has composed more than seventy piano compositions, some of which are used in this book. He and his wife, Helena, a former international judge of rhythmic gymnastics, have created several CDs and perform music regularly in their home city of Portland, Oregon.view less