Editing Gregorian chant (section)

===Melodic types===
Gregorian chant is, as 'chant' implies, vocal music. The text, the phrases, words and eventually the syllables, can be sung in various ways. The most straightforward is recitation on the same tone, which is called "syllabic" as each syllable is sung to a single tone. Likewise, simple chants are often syllabic throughout with only a few instances where two or more notes are sung on one syllable. "Neumatic" chants are more embellished and [[ligature (music)|ligatures]], a connected group of notes, written as a single compound neume, abound in the text. [[Melisma]]tic chants are the most ornate chants in which elaborate melodies are sung on long sustained vowels as in the Alleluia, ranging from five or six notes per syllable to over sixty in the more prolix melismata.{{sfn|Hoppin|1978a|pp=85–88}}

{{Listen|type=music|filename=Epistle for the Solemn Mass of Easter Day.ogg|title=Epistle for the Solemn Mass of Easter Day|description=Example of liturgical recitative in Gregorian chant}}
Gregorian chants fall into two broad categories of melody: [[recitative]]s and free melodies.{{sfn|Apel|1990|p=203}} The simplest kind of melody is the liturgical recitative. Recitative melodies are dominated by a single pitch, called the ''[[reciting tone]]''. Other pitches appear in melodic formulae for [[incipit]]s, partial [[cadence]]s, and full cadences. These chants are primarily syllabic. For example, the [[Collect]] for [[Easter]] consists of 127 syllables sung to 131 pitches, with 108 of these pitches being the reciting note A and the other 23 pitches flexing down to G.{{sfn|Hoppin|1978b|p=11}} Liturgical recitatives are commonly found in the [[Accentus Ecclesiasticus|accentus]] chants of the liturgy, such as the intonations of the Collect, [[Epistle]], and [[Gospel]] during the [[Mass (liturgy)|Mass]], and in the direct [[psalmody]] of the [[Canonical hours|Office]].

Psalmodic chants, which intone [[psalms]], include both recitatives and free melodies. Psalmodic chants include ''direct psalmody'', ''antiphonal chants'', and ''responsorial chants''.{{sfn|Hoppin|1978a|p=81}} In direct psalmody, psalm verses are sung without refrains to simple, formulaic tones. Most psalmodic chants are antiphonal and responsorial, sung to free melodies of varying complexity.

[[File:Evora06.jpg|thumb|Antiphonary with Gregorian chants]]
{{Listen|type=music|filename=Loquetur Dominus.ogg|title=''Loquetur Dominus'', Introit for Week XXXIV of Ordinary Time|description=Example of antiphonal psalmody in Gregorian chant
|filename2=De profundis.ogg|title2=''De profundis'', tract for the Requiem Mass|description2=Example of responsorial psalmody in Gregorian chant}}
Antiphonal chants such as the [[Introit]], and [[Communion (chant)|Communion]] originally referred to chants in which two choirs sang in alternation, one choir singing verses of a psalm, the other singing a refrain called an ''[[antiphon]]''. Over time, the verses were reduced in number, usually to just one psalm verse and the [[doxology]], or even omitted entirely. Antiphonal chants reflect their ancient origins as elaborate recitatives through the reciting tones in their melodies. Ordinary chants, such as the [[Kyrie]] and [[Gloria in Excelsis Deo|Gloria]], are not considered antiphonal chants, although they are often performed in antiphonal style.

Responsorial chants such as the [[Gradual]], [[Alleluia]], [[Offertory]], and the Office Responsories originally consisted of a refrain called a ''respond'' sung by a choir, alternating with psalm verses sung by a soloist. [[Responsory|Responsorial]] chants are often composed of an amalgamation of various stock musical phrases, pieced together in a practice called ''[[centonization]]''. Tracts are melismatic settings of psalm verses and use frequent recurring cadences and they are strongly centonized.

Gregorian chant evolved to fulfill various functions in the Roman Catholic liturgy. Broadly speaking, liturgical recitatives are used for texts intoned by deacons or priests. Antiphonal chants accompany liturgical actions: the entrance of the officiant, the collection of offerings, and the distribution of the Eucharist. Responsorial chants expand on readings and lessons.{{sfn|Hoppin|1978a|p=123}}

The non-psalmodic chants, including the [[Ordinary of the Mass]], [[Sequence (poetry)|sequences]], and [[hymn]]s, were originally intended for congregational singing.{{sfn|Hoppin|1978a|p=131}} The structure of their texts largely defines their musical style. In sequences, the same melodic phrase is repeated in each couplet. The strophic texts of hymns use the same syllabic melody for each stanza.