The Saint Martial School was a medieval school of music composition centered in the Abbey of Saint Martial, Limoges, France. Most active from the end of the ninth century until first half of the thirteenth century, some scholars prefer to describe its practices, music, and manuscripts and their countless innovations as 'Aquitanian'. It is known for the composition of tropes, sequences, and later versus compositions dealing with all forms of poetic and musical experiments (including polyphonic forms of discant and even troped organum). In this respect, it was an important precursor to the Notre Dame School. Adémar de Chabannes and his uncle Roger de Chabannes, who introduced Adémar in the craftship of a notating cantor, were important proponents of this school whose hands had only been recently identified and discovered by studies of James Grier between 1995 and 2005. Although they did neither invent a local variant of a vertically precise organisation of notation nor a new form of local tonary, they did reorganise existing chant manuscripts of the diocese Limoges, and they improved the libellum structure of a new type of sequentiary troper whose organisation was still young at their time, but played a key role for the Saint Martial school, the school of Winchester (e.g. GB-Ccc Ms. 473) following Wulfstan and the later Parisian Notre Dame school.

History of the Abbey Saint Martial de Limoges Many of the early musicological studies concerning a "Saint Martial school" had their focus on four manuscripts with remarkably innovative compositions dating back to the late eleventh and twelfth centuries, and this focus was mainly about polyphony. It was often assumed that these fragments derived from different Southern French monasteries, which were collected at the library of the Abbey. After its destruction, the manuscripts were collected and saved by the French king. According to their older collocations at the Bibliothèque nationale they were part of a large collection called "Saint-Martial". Due to the lack of cantor attributions in the rubrics, the many layers and hands who contributed to it, and many other codicological characteristics of the huge collection pointing at different destinations, the name of a "Saint Martial school" became soon a matter of discussion.

Sarah Fuller discussing the "myth of a Saint Martial school" argued that the fragments are rather a collective activity of the Abbey's librarians than a didactic activity of the Abbey's cantors and thus, questioned the term of a local school based at Limoges.Sarah provided her study with an accurate description of the four manuscripts and their nine libelli (as if the mess was not already sufficient) and identified the later additions in them, all on the base of her doctoral thesis . These manuscripts (F-Pn lat. 1139, 3549, 3719, and GB-Lbl Add MS 36881) were, it would seem, more likely collected and bound together by the librarian Bernard Itier (StM B & C) who obviously shared not the obsessions of modern musicologists concerning twelfth-century polyphony, and later librarians at Saint Martial Abbey. emphasized the fragmentary nature of these sources. They employ a "libellum" structure, often bound together from individual quaternio gatherings of different ages (F-Pn lat. 1139), unlike other sources during this period where polyphonic pieces are most often found added, by a later hand, at the end of quaternios of older monophonic manuscripts. Nevertheless, Bernard Itier was known as a precentor which means he was an educated cantor who could notate and was skilled in improvising as well as composing organa. Thus, Fuller's separation did not make any sense, and as a librarian he knew the treasures of his library, as well as Adémar de Chabannes' as other precious troper sequentiaries which he had bound, because he cared for them.

F-Pn lat. 1139 is the most important of these four manuscripts, called Saint-Martial A, B, C and D (StM A-D)Their former collocations of the Bibliothèque nationale were "Ms. Saint-Martial 100" (StM A), "Ms. Saint-Martial 174" (StM B), and "Ms. Saint-Martial 88" (StM C)., and consists of 235 folios. The earliest part of "Saint-Martial A" reaches from folio 32 to 118, has one dry point guide-line with diastematic Aquitanian point notation or partly agogic neumes (a clear sign that many notatores contributed to the troper) and this compilation can be dated back to the end of the eleventh century (1096-1099). It has two parts: After litanies and the lament of Rachel a so-called versarium (a huge versus collection which replaced the troper with tropes for proper mass chant), Benedicamus domino versus, a florid organum over a lesson, liturgical dramas, and polyphonic settings of Benedicamus domino sometimes with a tropus of an organal voice (ff.32r-62r). A notated lectionary with so-called epistles (ff.63r-73v), a prosulae collection as part of a sequentiary (ff. 80-107), and a troper fragment (as continuation of the versus collection or versarium) about ordinary mass chant (Sanctus, Kyrie tropes, and three about Agnus Dei) (ff. 73v-77v; 108v-117v) (ff.63r-118r). The later parts are a local proser of Limoges dating to the twelfth century (ff. 149r-228v) in Aquitanian point notation, and a collection of Marian hyms made as tropes of the antiphonary in square notation on red staff dating to the thirteenth century (ff. 119r-146v). This compilation was bound in 1245 and the main focus of musicological studies has been always the versarium (a collection of versus which had become a fancy genre replacing older collections of tropes and sequentiae). The oldest part was rich of poetic and musical experiments already done during the eleventh century, and since Limoges was obviously not its centre, "Aquitanian polyphony" became an alternative name to a so-called "Saint Martial school".

Despite of the concordances between these manuscripts, the collection includes many variants of a few compositions which would point precisely at the existence of such a school. The repertory combines innovative forms of poetry with innovative forms of musical composition, consisting of settings of proses.In the school of William of Volpiano (fully notated tonary) the term "prose" (Latin «prosa») usually refers mainly to the chant genre tractus replacing on certain feasts the alleluia verse and thus, the libellus collecting tractus was called "proser". In Aquitaine similar to the scribes of the Winchester Troper, the libellus proser referred to a collection of sequentiae, strophic poetry made over the prolonged responsoria («melodiae longissimae») of the alleluia verse. See the Ms. 887 (f.96r) where the proser follows the sequentiary rubrified «Incipiunt prose». The best expert on the topic is Richard who dedicated his doctoral thesis to it. The troper (poetic and melodic additions of proper and ordinary mass chant except tropes of the alleluia verse) was a separated book or libellus, while the Marian versus became a new genre of the later eleventh century which obviously replaced here the proper mass chant troper. The proper tropes are in fact completely missing in this manuscript. Despite of its name, sequentiary in Aquitaine referred less to a collection of sequentiae than to a collection of the untroped responsoria of the alleluia verses whose sections were marked by a round letter almost looking like the Greek minuscule δ (as it can be seen in the sequentiary of ms. 1118). The short psalm verses or non-scriptural verses had been left out, the incipits of the sequentiae such as «Cantemus organa» were written at the margin in red ink to identify the responsoria.See folio 87 recto (F-Pn lat. 887) with the rubric «Incipiunt sequencie», but only some exceptional sequences had been notated after the alleluia responsorium which created them by troping. The prosulae, non-scriptural tropes of the one or two short psalm verses between the repeated alleluia responsoria, were sometimes referred to the separated book (libellus) called "sequentiary". Thus, the proser (in this case a collection of sequentiae), the prosulae and the sequentiary were one complex in Aquitaine, and its contents were interconnected. Concerning Ms. 1139 there is only a prosulae collection, but some alleluia verses had been written on the last pages of the eleventh-century part, but were left without any neumes. The libellum versarium of the manuscript had three versus composed in Occitan language (ff.44r;48r-50r) and various cyclic compositions needed for liturgical drama (ff.52v-58r), and organa (ff.59v-61v, here used as general term for all forms of polyphony to embellish liturgical chant on the occasion of higher feasts). Even a polyphonic setting of liber sapientiae (Iesu filii Sirach 24:11-20) reading as florid organum (ff.44v-45v).A similar reading can be found in the lectionary rubrified as epistle for Saint Germain paraphrasing Iesu filii Sirach 44:16-27, 45:2-19, & 39:18, replacing Noah, Abraham and Moses by «sacerdos» (ff.72v-73v): the central words are «fungi sacerdotio et habere laudem».

The first 30 folios with parts from the thirteenth and twelfth centuries have conductus dedicated to Saint Martial, but were bound together in Paris under its first collocation "Regius 4458".

The exceptional character of elaborating liturgical chant either poetically or musically (and polyphony was just a few of many forms), often both at the same time, explains the confusion of musicologists studying these four manuscripts. Where they expected a systematic collection going through the calendar, they found instead loose collections with exceptional compositions of all kinds. Thus, it was rather normal that later additions were made for a few occasions (sometimes different realisations made over the same cantus), and they had to be added, where space was left. Some of these manuscripts are collections with unusual parts (like a lectionary rubrified as epistolary, «epistolarium», but it sometimes compiled extracts from the Old Testament and even changed them), but in their individual way composed (despite of many later additions which naturally confuse such a composition). Musicologists started with the most odd collections, calling their parts a troper (in fact, a versus collection called versarium), a sequentiary (prosulae collection) and a proser (mostly sequences, some additional tropes to the antiphonary). Others are just loose fascicles of a few folios and far too short to establish any order.

The confusion here is that they were bound together with a liturgical text-book of quite a different nature. Thus, even the later suggestion to call all four manuscripts "versaria" just prove one thing: that musicologists until the present day have problems to classify them—just for the way they are composed. But despite of all this confusion, the four manuscripts can be thanks to their datation and thanks to different strategies of using different types of notation studied as the continuous work in progress of a local school. The earliest layer which can be dated back to the eleventh century, has a prosulae collection and these recent compositions became in the other manuscripts dating to the twelfth century increasingly material to compose long pieces of polyphony.

Other musicological studies have attempted to identify a unifying centre for these sources (especially the eleventh-century part of StM A), such as Cluny rather than Limoges, and with reference to the Cluniac Monastic Association, Fleury and Paris (especially the Notre-Dame School, the Abbey of Saint Denis, and the Abbey Saint-Maur-des-Fossés). Questions about periphery and centre may be answered by the research of political and church history relative to Cluny.