Plainsong

Plainsong or plainchant (calque from the French plain-chant; Latin: cantus planus) is a body of chants used in the liturgies of the Western Church. When referring to the term plainsong, it is those sacred pieces that are composed in Latin text. Plainsong was the exclusive form of the Western Christian church music until the ninth century and the introduction of polyphony.

The monophonic chants of plainsong have a non-metric rhythm, which is generally considered freer than the metered rhythms of later Western music. They are also traditionally sung without musical accompaniment, though recent scholarship has unearthed a widespread custom of accompanied chant that transcended religious and geographical borders.