A hurdle for many people getting interested in classical music is that there is just so much of it. Where to start, if you weren’t conceived during intermission at Carnegie Hall and weaned on Mozart? Colgate University’s R. Ryan Endris sketches the way in a slender volume that opens in the place where many things began—in ancient Greece, where philosophers discovered a mathematical basis for music. Endris proceeds from Byzantine and Gregorian chant through polyphony and the inception of classical music as most of us know it in the courts of Renaissance Europe. Mozart is forced to share a chapter with Haydn, but Beethoven and Stravinsky get chapters of their own. Readable and illustrated in comic style by Joe Lee, Endris provides an overview of a complicated subject from Pythagoras through Philip Glass.