Several East Asian free reed instruments, including the "shō", were modeled on the "sheng", an ancient Chinese folk instrument later incorporated into more formal musical contexts. "Wubaduhesheng", one of the traditional chord formations played on the "sheng", involves a three-pitch cluster. Malayan folk musicians employ an indigenous mouth organ that, like the "shō" and "sheng", produces tone clusters. The characteristic musical form played on the "bin-baja", a strummed harp of central India's Pardhan people, has been described as a "rhythmic ostinato on a tone cluster."