Ars Nova
(Lat.: ‘new art’). 
In the most general terms Ars Nova is used as a synonym for ‘14th-century polyphony’ just as Ars Antiqua stands for ‘13th-century polyphony’. The concept of Ars Nova is based on the enormous new range of musical expression made possible by the notational techniques explained in Philippe de Vitry's treatise Ars nova (c1322). The term was first used as a historical slogan by Johannes Wolf in his Geschichte der Mensural-Notation (1904) in which the treatise was seen as one of the major turning-points in the history of notation; and it was perhaps the chapter titles rather than the specific content of Wolf's work that brought about the use of ‘Ars Nova’ to include all 14th-century French music in the work of subsequent scholars.

Several early 14th-century theorists referred to the idea of an Ars Antiqua, represented primarily by Franco, and an Ars Nova instituted by Philippe de Vitry (see, for instance, CoussemakerS, iii, 371, 408); but in historical terms the usefulness of the idea is supported more by the treatise Ars novae musicae (c1320) of Johannes de Muris, the 1324–5 bull of Pope John XXII decrying the musicians who were ‘novellae scholae discipuli’ and the reference in Jacobus of Liège's Speculum musice to ‘moderni cantores' and to ‘aliqui nunc novi’. That there was some awareness of a change in musical techniques and outlook in the years around 1320 is suggested also by the earliest music to exemplify the notation described in Philippe de Vitry's treatise, the motets for the roman de Fauvel copied into manuscript F-Pn fr.146 in 1316, some of them extensive works several times longer than the motets of the previous generation and displaying a range of notational values far greater than it was possible to notate with the previous Franconian and post-Franconian techniques.

Relatively few French musical sources survive from the years immediately following the Roman de Fauvel manuscript, and those few are fragments whose dating and provenance are subject to substantial disagreement, so there remain very few sources in the purest Ars Nova notation as described by philippe de Vitry. The term was therefore almost inevitably applied (by Wolf and many later scholars) to the work of Machaut and, since several Machaut manuscripts are from the early 15th century, to all French 14th-century music in spite of Schrade's insistence that after 1330 the style was no longer new. Indeed, so convenient was the label that it came to stand for all music between the Roman de Fauvel and the Renaissance: thus volume iii of the New Oxford History of Music is entitled Ars Nova and the Renaissance, 1300–1540 (London, 1960) and the major historical surveys in MGG follow the sequence ‘Ars Antiqua’, ‘Ars Nova’, ‘Renaissance’. In such surveys Ars Nova can include music from all parts of Europe and stretch to about 1420 (see Medieval).

Italian music of the 14th century is now more often separated off with the name ‘trecento’; but there is a reasonable (and strong) school of opinion that since the surviving repertory stretches from about 1325 to 1425 it is historically misleading to call it by a name that implies a division at the year 1400, and geographically separatist to use such an exclusively Italian name. Major considerations in support of excluding Italy from the idea of Ars Nova are: that Italian music until about 1370 was stylistically and notationally entirely different from French music; and that Italian notation evolved more gradually and a precise demarcation point between an Ars Antiqua and an Ars Nova in Italy cannot be established in any historically useful sense (see Clercx).

On the other hand it is hard to resist the claims of Nino Pirrotta (1966) that the fundamental change in both France and Italy in the years around 1320 was the same: that for the first time ‘it required that the length of every sound be precisely determined so that the different voices could proceed on schedule and fall precisely into the combinations of sound and rhythm determined by the composer’. While that was just the culmination of processes that had been in hand for the preceding half-century, it remains one of the most startling and important moments in the history of music. No historian has ever denied that French and Italian music in the first half of the 14th century are, in general, stylistically quite different; but it is too easy to overlook the range of styles within each tradition, to impose facile boundaries. Moreover, Pirrotta's analysis allows room for seeing the undeniable links between musical evolution in all parts of Europe, including England and the eastern parts of the empire.

A further narrowing down of the terminology has been effected by Günther who formulated the term Ars subtilior to designate music of the post-Machaut generation of composers, those musicians of an International Gothic who fused the styles of France and Italy, paving the way for the simpler styles of the 15th century. In a sense this terminology is again an attempt to transfer a description of a notational style (called by Apel ‘manneristic notation’) to denote a musical style. The difficulty in this analysis is that many simpler styles in French music co-existed with the intricate music of the Ars Subtilior; that is, the Ars Subtilior did not replace existing styles, and its techniques were not fundamentally different from what had existed before, merely more elaborate. But since this distinction has been generally accepted and has led to the French Ars Nova being considered to end about 1370, at a time when French and Italian styles were still clearly separated, there has been subsequently less force of opinion to support any references to an Italian Ars Nova.

It is therefore customary to use ‘Ars Nova’ to refer to French music from the Roman de Fauvel to the death of Machaut, for though this is not historically the most precise way of using the term, it is historiographically the most useful. At the same time it is worth observing that ‘Ars Nova’, like ‘Renaissance’, is a term found at many times in the course of history (see Schrade). Perhaps the most famous use outside the 14th century is that of Tinctoris (CoussemakerS, iv, 154), who described Dunstaple (d 1453) as ‘ut ita dicam, novae artis fons et origo’.

Ars Antiqua [Ars Veterum, Ars Vetus]
(Lat.: ‘old art’). 
A term used by a group of writers, mostly active in Paris in the early 14th century, to distinguish the polyphony and notation of the immediate past from the new practice of their own time, the Ars Nova (Ars Modernorum), especially that associated with Philippe de Vitry, Johannes de Muris and their circle in the 1310s and 20s. (The word ‘ars’, as understood in the Middle Ages, translates the Greek word techne, a ‘technique’ or ‘craft’, and has no aesthetic connotations.)

Among music theorists, the champion of the Ars Antiqua was Jacobus of Liège, who in his encyclopedic Speculum musice (1320s) upheld the authority of Franco of Cologne, Magister Lambertus (whom he called ‘Aristotle’) and Petrus de Cruce, and while criticizing the moderns defined the main virtues of the old practice: (1) modern composers wrote only motets and chansons, neglecting other genres such as organum, conductus and hocket (CSM, iii/7, p.89); (2) modern composers used a multiplicity of imperfect mensurations alongside perfect ones in their work, whereas the old practice, following Franco and Lambertus, adhered exclusively to perfection (CSM, iii/7, pp.86–8); (3) the moderns divided semibreves into smaller values, perfect and imperfect groups of minims and semiminims, whereas the followers of the Ars Antiqua divided breves only into semibreves in perfect mensuration, holding that the semibreve was indivisible (CSM, iii/7, pp.35–6, 51–3); (4) as a consequence, paradoxically, the rhythmic language used by the moderns was much more limited and inflexible than that of the adherents to the old practice (CSM, iii/7, pp.38–9); (5) the moderns engaged in a great deal of experimentation with notation, resulting in an inconsistent practice, whereas the followers of Franco had a clear and established tradition for notating their music (CSM, iii/7, pp.51–3); (6) the moderns indulged too much in quirky and capricious rhythmic movement,musica lasciva, while the followers of the old practice kept within the confines of a more restrained musica modesta (CSM, iii/1, p.60). From this it is evident that the Ars Antiqua is the musical practice of the latter half of the 13th century, preserved most comprehensively in manuscripts such as F-MOfH196, D-BAs Lit.115, and I-Tr Vari 42, and described by the theorists mentioned above, the many commentaries, abbreviationes, andcompendia based on Franco's Ars cantus mensurabilis, and the De musica of Johannes de Grocheio. Such manuscripts as B-Br19606 and F-Pn fr.146 (the Roman de Fauvel), both from the second decade of the 14th century, are transitional in a sense, containing works in both Ars Antiqua and Ars Nova. 

The definition of the term ‘Ars Antiqua’ is often extended now to include the music of the Notre Dame period and its main composers, Leoninus and Perotinus. The genres that Jacobus praised and the rhythmic idiom he discussed developed from this earlier tradition; and indeed, the repertories of organum and conductus belong properly to that tradition rather than to the period with which he was concerned. In this more comprehensive definition, then, the Ars Antiqua includes two large historical periods, the Notre Dame school, dating from about 1160 to about 1250 and preserved in manuscripts such as I-Fl Plut.29.1, D-W 628,D-W 1099, and E-Mn 20486, and the period from about 1250 to about 1320, specifically referred to by Jacobus. The former is characterized by liturgical polyphony with Latin texts and by modal rhythm and an emerging mensural notation; the latter is dominated by controlled mensural rhythm and a developed notation, and by the genre of the motet, above all the French motet, but it also saw the beginning of a written tradition of instrumental music and secular polyphonic song. The earlier genres of conductus and organum were extensively reworked in the light of the changed aesthetic that came with mensural rhythm; it is undoubtedly through such modernized versions that Jacobus knew the earlier repertory. Whatever merits the expanded definition of the Ars Antiqua may have, a distinctly new period, an Ars Nova, did emerge in the 1310s and 20s. While many of the innovations of the Ars Nova were indeed radical, many others represent extensions of the earlier practice; thus Philippe de Vitry expressly based his rhythmic system on the Ars Vetus of Franco. Sensitivity to these changes and expansions of Ars Antiqua practices on the part of modern and more conservative musicians alike doubtless moulded the rather polemical distinction Jacobus drew between the two artes.