Chants de l'Église de Rome - Vêpres (Ensemble Organum/Marcel Pérès)

Old Roman chant is a Medieval Latin plainchant tradition associated with the papal liturgy in Rome before the universal adoption of Gregorian chant. Preserved in 11th–12th‑century manuscripts yet reflecting much earlier practice, it represents a distinct Roman repertory rather than a mere variant of the later Gregorian standard. It is monophonic, a cappella, and modal, typically more melismatic and ornate than most Gregorian melodies. The chant follows the accent and syntax of sacred Latin texts with a flexible, speech‑like rhythm. It was performed by trained clerical choirs (scholae cantorum) within the Mass and Office, using formulaic melodic patterns (centonization) and the eight ecclesiastical modes.

Plainchant (cantus planus) is the monophonic, unaccompanied chant of the Western Christian liturgy. Sung in Latin (with occasional Greek), it uses modal scales rather than major–minor tonality and unfolds in flexible, speech-like rhythms shaped by the sacred text. Melodically, plainchant ranges from simple syllabic formulas for reciting psalms to ornate melismatic lines for processional and festal moments. It is performed in unison by a schola or congregation, often organized antiphonally or responsorially across the liturgical actions of the Mass and the Divine Office. Its austere sonority, modal color, and text-centered phrasing give it a contemplative, timeless quality.