Gregorian chant is an early medieval period music which is monophonic both sacred and secular song of the Roman Catholic. Gregorian chant developed mainly in the Frankish lands of western and central Europe during the 9th and 10th centuries, with later additions and reductions.
Gregorian melodies are transcribed using neumes, an early from of musical notation from which the modern five-line staff developed during the 16th century. Gregorian chant played a fundamental role in the development of the polyphony.
Gregorian chant was traditionally sung by choirs of men and boys in churches, or by women and men of religious orders in their chapels. It is the music of the Roman Rite, performed in the Mass and the monastic office. Although the Gregorian chant is no longer obligatory, the Roman Catholic church still officially consider it the music the most suitable for worship. In the 20th century, it became popular again in the music mainstream with modern song in a Gregorian chant music.