performed to mahori music, celebrates the various cultural and ethnic groups of Cambodia. Folk dances originated in the villages and are performed, for the most part, by the villagers for the villagers. The movements are less stylised and the clothing worn is that of the people the dancers are portraying, such as hill tribes, Chams or farmers. Typically faster-paced than classical dance, folk dances display themes of the "common person" such as love, comedy or warding off evil spirits. Social dances are those performed by guests at banquets, parties or other informal social gatherings. Khmer traditional social dances are analogous to those of other Southeast Asian nations. Examples include the circle dances Romvong and Romkbach as well as Saravan and Lam Leav. Modern western popular dances including Cha-cha, Bolero, and the Madison, have also influenced Cambodian social dance. Libraries The National Library of Cambodia opened in 1924. It suffered much destruction during the Khmer Rouge era. Music Traditional Cambodian music dates back as far as the Khmer Empire. Royal dances like the Apsara Dance are icons of the Cambodian culture as are the Mahori ensembles that accompany them. More rural forms of music include Chapei and Ayai. The former is popular among the older generation and is most often a solo performance of a man plucking a Cambodian guitar (chapei) in between a cappella verses. The lyrics usually have moral or religious theme. A Yai can be performed solo or by a man and woman and is often comedic in nature. It is a form of lyrical poetry, often full of double entendres, that can be either scripted or completely impromptu and ad-libbed. When sung by a duo, the man and women take turns, "answering" the other's verse or posing riddles for the other to solve, with short instrumental breaks in between verses. Pleng kaah (lit. "wedding music") is a set of traditional music and songs played both for entertainment and as accompaniment for the various ceremonial parts of a traditional, days-long Khmer wedding. Cambodian popular music is performed with western style instruments or a mixture of traditional and western instruments. Dance music is composed in particular styles for social dances. The music of crooner Sinn Sisamouth, Ros Sereysothea, and Pen Ran from the 1960s to the 1970s is considered to be the classic pop music of Cambodia. During the Khmer Rouge Revolution, many classic and popular singers of the