August 15 of the lunar calendar is a traditional Chinese festival---the Mid-Autumn Festival. Perhaps "it is on the festive occasions that one misses his dear most", every year on that day, people far away from home will try to come back to their hometown, sitting together enjoying family reunion. Therefore, it is a happy festival, and a joyous festival as well. There are legends and folk customs unique to the Mid-Autumn Festival. Its cultural tradition has been handed down until now.
- The practice of moon sacrifice originates from moon worship of ancestors in the remote past. Later the moon as a celestial body was personified and became the Moon God, which was called God of Night by the imperial families in the past generations. When Taoism prospered, the Moon God was called Taiyin Xingjun (Stellar Sovereign of Supreme Yin). And the common folks mostly believe the Moon God is a female named Chang Er, and intimately call it "Moon Aunti" or "Moon Sister".
After moon sacrifice as a seasonal sacrificial ritual was listed as the routine of imperial sacrificial ceremony, the custom was seldom practiced in the folk life. Great gods like the sun and the moon which represent Yin and Yang respectively could only be communicated by the imperial family, and moon sacrifice became the exclusive right of the imperial family.
- Emperor Xuanzong Rambling about the Moon Palace
Legend has it that once Emperor Xuanzong together with Shen Tianshi (Taoist master) and Taoist Hong Du was watching the moon on the Mid-Autumn Day. Emperor Xuanzong wanted to ramble on the moon palace out of whim. So Shen Tianshi did witchcraft and the three rode the cloud to see the moon palace. However, the palace was heavily guarded and they could not enter. So they stood outside the palace to overlook Changan City. Then all of a sudden, heavenly music was heard from somewhere. Well versed in music, Emperor Xuanzong memorized the melody in heart. Later, recalling the music he heard outside the moon palace, Emperor Xuanzong added lyrics and choregraphy to the music, which was the well-known "Song of Rainbow Skirt and Robe of Feathers".