Gregorian chant
Most people think that the liturgy of the Roman Mass was put together during the 7th century. In 785-786, Pope Hadrian I sent some Roman chants to the court of Charlemagne. Later this music developed into the system of eight modes. This music, together with some new chants to complete the liturgical year, became known as "Gregorian." This chant was probably named after Pope Gregory the Great.