In the tragic art that developed greatly around the 4th century BC, we can see some of the musical forms of the time reflected in the Dionysian odes, Apollonian odes and drinking songs in the tragic chorus. During the Hellenistic period, music theory was also quite developed. For example, according to Pythagoras' (about 580 BC to about 500 BC) chord length ratio theory, music is harmonious with the movement of celestial bodies and all things, and there is also a relationship between numbers. Another example is the moral influence of music advocated by Plato (approximately 428 BC ~ 322 BC), Aristotle (approximately 384 BC ~ 322 BC) and others, who believed that music has a profound influence on the human soul. , has a significant impact on the improvement of character, and opposes the measurement of music art as entertainment, pointing out that music should be included in the education curriculum of young people.