The central rite is len dong, mounting the medium. A ceremony runs for hours and proceeds through a sequence of spirits, each of whom is received in turn. The medium sits with assistants who drape a cloth over the head between spirits and dress the body in the costume of the next arrival, and the arrival is signalled by the fingers held up to indicate which palace the spirit belongs to. While present the spirit may dance, may smoke or drink, gives blessings, and distributes loc, small gifts of money, fruit and other goods that carry the spirit favour into the household of whoever receives them.
The music is not accompaniment. Chau van is a sung and instrumental repertoire composed for the ceremony, performed by a band with the moon lute at its centre, and each spirit has its own melodies and rhythms. The musicians follow the medium and also lead, since the change of tune is part of what brings the next spirit forward. Chau van is now performed on concert stages as well, which practitioners regard variously.
The practice was discouraged as superstition through much of the twentieth century and was carried on quietly. It has revived very strongly since economic liberalisation in the 1990s, in a form that involves considerable expenditure on costume, offerings and musicians, and the relation between devotion and display is argued about within the community. UNESCO inscribed the practice on its representative list of intangible cultural heritage in 2016.