ARS ANTIQUA
Ars antiqua is the name given, in contrast to the *Ars nova* (v.) of the 14th century, to sacred composition from the early period of polyphony (9th–13th centuries), which is usually understood within the theory of the Franco school and the technical genres of “organum” or “diaphonia,” later “discantus,” including other forms such as “rondellus,” “conductus,” “copula,” “motetus,” and “hocket.” This period, in which music, drawing largely from the purest sources of the liturgy, enriched itself with a vast sacred repertoire in which the vital sap of Gregorian chant remained unchallenged, can be divided into three phases, each lasting about a century: the first, opened by Hucbald of Saint-Amand, a distinguished Benedictine theorist of the 9th century, closed by the *Micrologus* (1030) of his famous confrere Guido d’Arezzo (v.); the second closed by the *Magnus Liber organi* of Léonin, and the third culminating in the reforming and innovative work of his successor Pérotin (v.).
Of the two kinds of sources—monuments of practical music and theoretical treatises—the latter are, in the first phase, the only aid for the study of primitive polyphony. Hucbald, in the 19 chapters of the *Musica Enchiriadis*, suggests various types of diaphony with harmonic intervals (“symphoniae”) of a 4th, 5th, and octave between the *vox principalis* (the chant taken from the Gregorian repertoire) and the *vox organalis* (the added voice), while Guido, in chapters 18 and 19 of the *Micrologus*, proposes major 2nd, major and minor 3rds, and especially the 4th, rejecting the minor 2nd and the 5th.
The second phase provides important treatises, such as the anonymous *Ad organum faciendum* from Milan (Bibl. Ambros., ms. M 17 Suppl., c. 1100), the 12 rules of *Quicumque vult dechanter* (11th–12th c.; Paris, Bibl. Nat., f. lat. 15139, formerly St-Victor 813), the *Discantus positio vulgaris* (attributed to Robert de Sablon or to J. de Garlandia), of the 12th c., the *Epistola ad Fulgentium* by J. Cotto (also 12th c.), as well as precious monuments of practical music: we may recall, for example, three two-voice “organa,” including the trope on the Kyrie *Cunctipotens Genitor Deus* and the alleluia *Justus ut palma* from the aforementioned Ambrosian manuscript, the five two-voice alleluias added in the 11th century to a *Musica Enchiriadis* from the 9th–10th century (Chartres, Bibl. Munic., 130 [148]), and the *Winchester Troper* (Cambridge, Corpus Christi College 473). To these must be added the “organa” from Saint-Martial of Limoges, preserved in four manuscripts now in Paris (Bibl. Nat., f. lat. 1139, 3549, and 3719) and in London (Br. Mus., Add. 36681).
The primitive two-voice “organum” in parallel motion, which had gradually been transformed into discant through the prevalence of contrary motion, now gains additional voices: from the three-voice discant (triplum) with intervals of 5th and octave proposed by Franco of Cologne, forms are developed that place above the *tenor* (Gregorian chant) a *duplum*, also called “medius cantus” or “motetus” (from which the form takes its name), a *triplum* (“tertius cantus” or “discantus”), and often also a *quadruplum* and a *quintuplum*.
The third phase adds to discant, besides contrary motion, that mensuralism which, already prefigured by modal rhythm inspired by the metrical schemes of verse, is now developed by the theorists of the Franco school (Petrus de Cruce, J. de Garlandia, Franco of Paris, and Franco of Cologne, 13th c.) and expressed graphically in the new notation with signs relating to the different durations of sounds. In practical music, we reach the culminating point of the entire *ars antiqua*, namely the flowering of the school of the cathedral of Paris, which, with Léonin (mid-12th c.), had placed itself at the center of the musical world of its time.
The oldest manuscript of the Parisian choir is the Wolfenbüttel codex Helmst. 628, but the richest collection is in the *Antiphonarium Mediceum* (Florence, Bibl. Mediceo-Laur., Plut. XXIX, 1), a true jewel of art. In other manuscripts, moreover, we find pieces with texts no longer in Latin but in French, an indication of that process of secularization and of that divergent movement from pure Gregorian tradition which would culminate in the Italian (especially Tuscan) and French *Ars nova* (v.) of the 14th century.