Editing Gregorian chant (section)

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Gregorian chant was originally used for singing the [[Canonical hours|Office]] (by male and female religious) and for singing the parts of the [[Mass (liturgy)|Mass]] pertaining to the lay faithful (male and female), the celebrant (priest, always male) and the choir (composed of male ordained clergy, except in convents). Outside the larger cities, the number of available clergy dropped, and lay men started singing these parts. The choir was considered an official liturgical duty reserved to clergy, so women were not allowed to sing in the ''[[Schola Cantorum (disambiguation)|Schola Cantorum]]'' or other choirs except in [[convent]]s where women were permitted to sing the Office and the parts of the Mass pertaining to the choir as a function of their consecrated life.{{sfn|Neuls-Bates|1996|p=3}}

Chant was normally sung in unison. Later innovations included ''[[Trope (music)|tropes]]'', which is a new text sung to the same melodic phrases in a melismatic chant (repeating an entire Alleluia-melody on a new text for instance, or repeating a full phrase with a new text that comments on the previously sung text) and various forms of ''[[organum]]'', (improvised) harmonic embellishment of chant melodies focusing on octaves, fifths, fourths, and, later, thirds. Neither tropes nor organum, however, belong to the chant repertory proper. The main exception to this is the sequence, whose origins lay in troping the extended [[melisma]] of [[Alleluia]] chants known as the [[jubilus]], but the sequences, like the tropes, were later officially suppressed. The [[Council of Trent]] struck sequences from the Gregorian corpus, except those for [[Easter]], [[Pentecost]], [[Corpus Christi (feast)|Corpus Christi]] and [[All Souls' Day]].

Not much is known about the particular vocal stylings or performance practices used for Gregorian chant in the Middle Ages. On occasion, the clergy was urged to have their singers perform with more restraint and piety. This suggests that virtuosic performances occurred, contrary to the modern stereotype of Gregorian chant as slow-moving mood music. This tension between musicality and piety goes far back; [[Pope Gregory I|Gregory the Great]] himself criticized the practice of promoting clerics based on their charming singing rather than their preaching.{{sfn|Hiley|1995|p=504}} However, [[Odo of Cluny]], a renowned monastic reformer, praised the intellectual and musical virtuosity to be found in chant:

{{blockquote|For in these [Offertories and Communions] there are the most varied kinds of ascent, descent, repeat..., delight for the ''cognoscenti'', difficulty for the beginners, and an admirable organization... that widely differs from other chants; they are not so much made according to the rules of music... but rather evince the authority and validity... of music.{{sfn|Apel|1990|p=312}}}}

True antiphonal performance by two alternating choruses still occurs, as in certain German monasteries. However, antiphonal chants are generally performed in responsorial style by a solo cantor alternating with a chorus. This practice appears to have begun in the Middle Ages.{{sfn|Apel|1990|p=197}} Another medieval innovation had the solo cantor sing the opening words of responsorial chants, with the full chorus finishing the end of the opening phrase. This innovation allowed the soloist to fix the pitch of the chant for the chorus and to cue the choral entrance.