Adorate Deum: Gregorian Chant for the Proper of the Mass

Early music is a modern performance movement devoted to the repertoire of the Medieval, Renaissance, and early Baroque eras (roughly before c. 1750), approached with historically informed performance (HIP) practices. It emphasizes period instruments (or faithful replicas), historical tunings and temperaments, original notations and sources, and performance conventions documented in treatises of the time. The sound world ranges from monophonic chant and modal organum, to intricate Renaissance polyphony, to the emergence of basso continuo and dramatic affect in the early Baroque. Rather than being a single historical style, early music is a contemporary practice of reviving diverse pre‑Classical musics with scholarly rigor and artistic vitality.

Gregorian chant is the central Western tradition of plainchant: a monophonic, unaccompanied sacred song in Latin (and occasionally Greek) used in the Roman Catholic liturgy. It employs free rhythm guided by the prosody of the text rather than by strict meter, and is sung in unison by clerics or scholas. Its melodies are organized by the system of eight church modes, with characteristic finalis (final), tenor/reciting tones, and melodic formulas. Repertoires include the Proper and Ordinary of the Mass (e.g., Introit, Gradual, Alleluia, Offertory, Communion, Kyrie, Gloria, Credo, Sanctus, Agnus Dei) and the Divine Office (e.g., Antiphons, Responsories, Hymns, Psalms). Although legend credits Pope Gregory I, modern scholarship sees Gregorian chant as a Carolingian synthesis of Old Roman and Gallican chants, standardized across Frankish realms and later the broader Latin West.

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.