Tibetan music often involves chanting in Tibetan or Sanskrit, as an integral part of the religion. These chants are complex, often recitations of sacred texts or in celebration of various festivals. Yang chanting, performed without metrical timing, is accompanied by resonant drums and low, sustained syllables. Other styles include those unique to the various schools of Tibetan Buddhism, such as the classical music of the popular Gelugpa school, and the romantic music of the Nyingmapa, Sakyapa and Kagyupa schools.