chant, general name for one-voiced, unaccompanied, liturgical music. Usually it refers to the liturgical melodies of the Byzantine, Russian Orthodox, Roman Catholic, and Anglican churches and is analogous to cantillation in Jewish liturgical music, Qur'anic chanting in Islam, and single-line chanting in other religions. Roman Catholic chant, commonly called Gregorian chant or plainsong, is diatonic, modally organized (see mode), and has a free rhythm determined by the text. Anglican chant is a harmonized, metrical adaptation to English texts of the Gregorian method of psalm singing, in which a short melody is adjusted to the length of different psalm verses by repeating one tone, the recitation tone, for any number of words in the text. The texts of Anglican chant, used in many Protestant churches, are from the Book of Common Prayer.