In the early 11th century an Italian monk named Guido of Arezzo faced a challenge when teaching Gregorian chants took nearly a decade of memorization. He developed a staff of four horizontal lines with defined pitches and introduced ut re mi fa sol la for sight singing. His innovative system reduced training time to just a couple of years but stirred envy in his fellow monks at Pomposa Abbey who exiled him. In Arezzo he refined his method, paving the way for the written music used even a thousan