Author Julie Ellis and illustrator Phyllis Hornung Peacock team up once again to explore Pythagorean ratios in Pythagoras and the Ratios, the humorous sequel to What s Your Angle, Pythagoras? Pythagoras and his cousins want to win a music contest, but first they must figure out how to play their instruments in tune, something that s never been done before. While trying to fix the problem, Pythagoras makes an important discovery—notes that sound pleasant together have a certain mathematical relationship. When Pythagoras applies this ratio to his cousins pipes and lyres, the result is music to the ears.