CLOAKED in mystery and shrouded by clouds in the Himalayan mountains, Tibet has been isolated from the rest of the world for centuries. For years it has been cut off from the tourist boom sweeping other parts of China. Last year, however, it was announced that Tibet would undergo an ''all-round opening up to the outside world'', in the hope that not only travellers would bring much-needed foreign currency, but that Tibetan culture could receive the attention it deserved. Helping in this quest is the Hongkong Arts Festival, which this year is bringing in the 168-member Tibetan Song and Dance Troupe. The troupe specialises in the songs and dances of Tibet's people, from native Tibetans to Hans, Muslims and the nomadic Drokpa people. Its repertoire includes both contemporary and traditional works in the religious, court and folk genres. Essentially, the troupe has taken on the task of perpetuating, revitalising, recording and developing Tibet's music and dance. In the 30 years since its founding, the Tibetan Song and Dance Troupe has performed throughout the country, from the pasture lands of the high plateaux to the steep crags of the border regions. It has also travelled the length and breadth of China. The troupe has also been to Nepal, Denmark, Iceland, Sweden, Finland, the United States and numerous arts festivals throughout the world. Like most ancient cultures, the Tibetans use and have used their music and movement to record events, to celebrate both religious and popular festivals, and to tell stories. The piece A Grand Prayer Ceremony on the Snowland, for example, originated in Lhasa in 1409 as a Buddhist prayer service to hasten the coming of the Maitreya Buddha. It was later combined with other festivities celebrating the Tibetan Lunar New Year, but was all but abandoned by the early 20th century. In 1986, the Panchen Lama was in Lhasa to attend the Grand Prayer ceremony, which had not taken place in the past 20 years. Based on the actual Grand Prayer festival, Snowland introduces a new realm of sound that reveals the spirituality of the Tibetan people. In 1989 it was first performed by the Tibetan Song and Dance Troupe at the Second Chinese National Arts festival in Beijing, and is now a regular feature of the troupe's repertoire. Religion and superstition come together in both the Black Hat Dance and the Deer Dance. Both are traditionally performed by monks, part of elaborate rituals intended to repel evil and misfortune. The shanak, or ''black hat'' dance, has its roots in the ninth century when it was used to rid Tibet of the shamanist king, Lang Darma. Music in the Deer Dance, meanwhile, represented the Wind God, who travels on a deer, and honours the Mother Goddess of the Earth, whom Tibetans believe protects the land and its households. Court music and dance combine for Carl, which used to be performed in the courts of kings and at major Buddhist ceremonies. The version which the Tibetan Song and Dance Troupe will perform in Hongkong was personally taught and sanctioned by the chief musician of the 14th Dalai Lama. The Re Ba Folk Dance comes from the eastern part of Tibet. In the past, itinerant performers made their living by performing this dance at village gatherings. The Tibetan Song and Dance Troupe performs at the Cultural Centre Grand Theatre on February 18-21.