Gregorian chant is a form of monophonic sacred song that was central to Western plainchant tradition in the Roman Catholic Church. Pope Gregory I, who was Pope from 590 to 604, is considered the founder of the medieval papacy and was influential in spreading and establishing Gregorian chant. Characteristics of Gregorian chant include being monophonic, using free meter and modal scales, based on Latin liturgy, and notated using neumes.