The actual Birth of Scientific Thought is attributed to Pythagoras and the Pythagoreans, a story that today we can reconstruct through "The Fragments of the Pythagoreans". From the 6th-5th century BC of Pythagoras to 500 AD of Severino Boethius, the succession of fragments of the Pythagoreans is the only written testimony that survived the destruction of the fabulous Library of Alexandria, the Temple of Knowledge in Antiquity. The reconstruction of this history, interrupted for almost a thousand years, reappears in the Middle Ages of 1400 and in the sixteenth century Renaissance: the "Quadrivium" represents Music together with Mathematics, Geometry and Astronomy, the Liberal Arts which still coexisted in that era and who apply Pythagorean thought to Art, according to systems that we still commonly use today. The Monochord of Pythagoras and the 13 Sounds of Music, the construction of the "Pythagorean scale" compared with the sounds of the keyboard of a modern piano, to understand the archaic origin of the world of sounds, and how we perceive it today: the numbers unfold symmetrically within the world of sounds.