as well as wind instruments called bawu (巴乌) and mabu (马布). The Yi also play the hulu sheng, though unlike other minority groups in Yunnan, the Yi do not play the hulu sheng for courtship or love songs (aiqing). The kouxian, a small four-pronged instrument similar to the Jew's harp, is another commonly found instrument among the Liangshan Yi. Kouxian songs are most often improvised and are supposed to reflect the mood of the player or the surrounding environment. Kouxian songs can also occasionally function in the aiqing form. Yi dance is perhaps the most commonly recognized form of musical performance, as it is often performed during publicly sponsored holidays and/or festival events. Literature Artist Colette Fu, great-granddaughter of Long Yun has spent time from 1996 till present photographing the Yi community in Yunnan Province. Her series of pop-up books, titled We are Tiger Dragon People, includes images of many Yi groups. Religion Bimoism Other religions In Yunnan, some of the Yi have adopted Buddhism as a result of exchanges with other predominantly Buddhist ethnic groups present in Yunnan, such as the Dai and the Tibetans. The most important god of Yi Buddhism is Mahākāla, a wrathful deity found in Vajrayana and Tibetan Buddhism. In the 20th century, many Yi people in China converted to Christianity, after the arrival of Gladstone Porteous in 1904 and, later, medical missionaries such as Alfred James Broomhall, Janet Broomhall, Ruth Dix and Joan Wales of the China Inland Mission. According to missionary organization OMF International, the exact number of Yi Christians is not known. In 1991 it was reported that there were as many as 1,500,000 Yi Christians in Yunnan Province, especially in Luquan County where there are more than 20 churches. Medicine The Yi are known for the extent of their inter-generational transmission of traditional medicine through oral tradition and written records. Their traditional medicine system has been academically inventoried. Since the prefecture the Yi medicinal data was collected from also contains the cave containing human-infectable SARS clades and it is known that people living in the vicinity SARS caves show serological signs of past infection, it has been suggested that the Yi were repeatably exposed to coronavirus over their history, passively learned to medicinally fend off coronavirus infection centuries ago, and committed the results into their inter-generational record of medicinal indications. Distribution County-level distribution of the Yi 2000 census in China. (Only