Ars Nova

Ars nova is the early-fourteenth-century French style that succeeded the ars antiqua and introduced a new rhythmic vocabulary. Its main technical innovation, codified in Philippe de Vitry's treatise of the same name (c. 1322), was the notation and use of duple and triple division at every level — semibreves and minims now subdivided as freely as longs and breves had before. The signature compositional device is isorhythm: a repeating rhythmic pattern (talea) imposed on a repeating melodic pattern (color) of different length, producing a slow-moving structural lattice in the tenor voice. Settings are usually for three or four voices; secular forms include the ballade, rondeau and virelai, with sacred output dominated by the motet and, at the end of the period, the polyphonic mass.

Vitry (1291-1361), bishop, diplomat and composer, gave the period its theoretical foundation. Guillaume de Machaut (c. 1300-1377), poet and canon of Reims Cathedral, was its great musical synthesizer — the first composer whose complete works survive under a single attribution. Machaut's 'Messe de Nostre Dame' (c. 1365) is the earliest known complete polyphonic mass cycle by one composer. The end of the century saw the experimental ars subtilior, a hyper-complex offshoot at the papal court of Avignon, before fifteenth-century Burgundian composers simplified the language back into what we now call the early Renaissance.

Don't try to count all the voices at once. Instead, follow the top voice (cantus) as a sinuous melodic line and feel the lower voices as architecture. In an isorhythmic motet, the tenor's rhythmic pattern will recur many times — once you've heard the talea on its first pass, you start to feel its returns underneath everything else. Machaut's rondeau 'Ma fin est mon commencement' literalizes the period's mathematical bent: the music is its own reverse.

Machaut's 'Messe de Nostre Dame' (c. 1365) in a recording by The Hilliard Ensemble or Diabolus in Musica is the long-form entry. For a single song, 'Douce dame jolie' (a monophonic virelai, c. 1350) is the most-played short piece in the repertoire.

Ars nova translates literally as 'new art,' and contemporaries treated it as cutting-edge experimentation. Pope John XXII issued a bull in 1324 attacking its rhythmic complexity as a corruption of church music — an early case of the papacy weighing in on a notational innovation.