(Book). Ever noticed that many of the world's most influential drummers have a deep understanding of music and also know how to play another instrument? Modern Drummer founder and publisher Ron Spagnardi has, and with this new book/CD pack, he sets out to teach drummers the essentials of theory and harmony using a keyboard. He covers: major scales; basic chord structure; inversions; diatonic harmony; chord voicings, extensions and progressions; and more vital topics.