Editing Gregorian chant (section)

==Influence==

===Medieval and Renaissance music===
Gregorian chant had a significant impact on the development of [[medieval music|medieval]] and [[Renaissance music]]. Modern staff notation developed directly from Gregorian neumes. The square notation that had been devised for plainchant was borrowed and adapted for other kinds of music. Certain groupings of neumes were used to indicate repeating rhythms called [[rhythmic mode]]s. Rounded noteheads increasingly replaced the older squares and lozenges in the 15th and 16th centuries, although chantbooks conservatively maintained the square notation. By the 16th century, the fifth line added to the [[staff (music)|musical staff]] had become standard. The [[bass clef]] and the [[Flat (music)|flat]], [[Natural sign|natural]], and [[sharp (music)|sharp]] accidentals derived directly from Gregorian notation.{{sfn|Bent|Hughes|Provine|Rastall|2001}}

Gregorian melodies provided musical material and served as models for tropes and [[liturgical drama]]s. Vernacular hymns such as "[[Christ ist erstanden]]" and "[[Nun bitten wir den Heiligen Geist]]" adapted original Gregorian melodies to translated texts. Secular tunes such as the popular Renaissance "[[In Nomine]]" were based on Gregorian melodies. Beginning with the improvised harmonizations of Gregorian chant known as [[organum]], Gregorian chants became a driving force in medieval and Renaissance [[polyphony]]. Often, a Gregorian chant (sometimes in modified form) would be used as a ''[[cantus firmus]]'', so that the consecutive notes of the chant determined the harmonic progression. The Marian antiphons, especially ''Alma Redemptoris Mater'', were frequently arranged by Renaissance composers. The use of chant as a cantus firmus was the predominant practice until the [[Baroque]] period, when the stronger harmonic progressions made possible by an independent bass line became standard.

The Catholic Church later allowed polyphonic arrangements to replace the Gregorian chant of the Ordinary of the Mass. This is why the Mass as a compositional form, as set by composers like [[Giovanni Pierluigi da Palestrina|Palestrina]] or [[Wolfgang Amadeus Mozart|Mozart]], features a Kyrie but not an Introit. The Propers may also be replaced by choral settings on certain solemn occasions. Among the composers who most frequently wrote polyphonic settings of the Propers were [[William Byrd]] and [[Tomás Luis de Victoria]]. These polyphonic arrangements usually incorporate elements of the original chant.