Jongmyo Jeryeak was performed at the Jongmyo Shrine during ceremonies held for the eternal repose of the ancestors of Joseon’s kings. Each procedure of the ceremony involved the performance of various pieces of music, such as Botaepyeong and Jeongdaeeop, to praise the royal ancestors' virtues, and dances such as Botaepyeong and Jeongdaeeop. The music was originally composed in 1447, during the reign of King Sejong, for performance at royal banquets, but was modified in 1464, during the reign of King Sejo, for performance at memorial rites held to honor the royal ancestors of the dynasty. The ritual performance of music and dance, consisting of eleven works for each Botaepyeong and Jeongdaeeop, is still held on the first Sunday of May. This valuable heritage, which has been handed down for almost 600 years, is now at the top of Korea’s Important Intangible Cultural Heritage list and has been inscribed on the UNESCO's Representative List of Intangible Cultural Heritages of Humanity.