Editing Gregorian chant (section)

===Notation===
[[File:Neume2.jpg|thumb|Offertory ''Iubilate deo universa terra'' in unheightened neume]]{{Main|Neume}}
The earliest notated sources of Gregorian chant (written {{Circa|950|lk=no}}) used symbols called ''[[neume]]s'' (Gr. sign, of the hand) to indicate tone-movements and relative duration within each syllable. A sort of musical stenography that seems to focus on gestures and tone-movements but not the specific pitches of individual notes, nor the relative starting pitches of each neume. Given the fact that Chant was learned in an oral tradition in which the texts and melodies were sung from memory, this was obviously not necessary. The neumatic manuscripts display great sophistication and precision in notation and a wealth of graphic signs to indicate the musical gesture and proper pronunciation of the text.
Scholars postulate that this practice may have been derived from [[cheironomy|cheironomic]] hand-gestures, the [[ekphonetic]] notation of [[Byzantine chant]], punctuation marks, or diacritical accents.{{sfn|Levy|Emerson|Bellingham|Hiley<!-- |Zon -->|2001|loc=§6.1}} Later adaptations and innovations included the use of a dry-scratched line or an inked line or two lines, marked C or F showing the relative pitches between neumes. Consistent relative heightening first developed in the Aquitaine region, particularly at [[Saint Martial|St. Martial de Limoges]], in the first half of the eleventh century. Many German-speaking areas, however, continued to use unpitched neumes into the twelfth century. Additional symbols developed, such as the ''custos'', placed at the end of a system to show the next pitch. Other symbols indicated changes in articulation, duration, or tempo, such as a letter "t" to indicate a [[tenuto]]. Another form of early notation used a system of letters corresponding to different pitches, much as [[Shaker music]] is notated.

[[File:gregorian chant.gif|frame|''[[Liber usualis]]'' in square notation (excerpt from the ''Kyrie eleison (Orbis factor)'')]]
By the 13th century, the neumes of Gregorian chant were usually written in ''square notation'' on a four-line staff with a clef, as in the ''Graduale Aboense'' pictured above. In square notation, small groups of ascending notes on a syllable are shown as stacked squares, read from bottom to top, while descending notes are written with diamonds read from left to right. When a syllable has a large number of notes, a series of smaller such groups of neumes are written in succession, read from left to right. The [[oriscus]], [[quilisma]], and [[liquescent]] neumes indicate special vocal treatments, that have been largely neglected due to uncertainty as to how to sing them. Since the 1970s, with the influential insights of Dom {{ill|Eugène Cardine|fr}} (see below under 'rhythm'), ornamental neumes have received more attention from both researchers and performers.
B-flat is indicated by a "b-mollum" (Lat. soft), a rounded undercaste 'b' placed to the left of the entire neume in which the note occurs, as shown in the "Kyrie" to the right. When necessary, a "b-durum" (Lat. hard), written squarely, indicates B-natural and serves to cancel the b-mollum. This system of square notation is standard in modern chantbooks.