Editing Polyphony (section)

===Historical context===
European polyphony rose out of [[melismatic]] ''[[organum]]'', the earliest harmonization of the chant. During the 12th century, composers such as [[Léonin]] and [[Pérotin]] developed the {{lang|la|organum}} that had been introduced centuries earlier, and also added a third and fourth voice to the now homophonic chant. In the 13th century, the chant-based tenor was becoming altered, fragmented, and hidden beneath secular tunes, obscuring the sacred texts as composers continued to develop polyphonic techniques. The lyrics of love poems might be sung above sacred texts in the form of a [[trope (music)|trope]], or the sacred text might be placed within a familiar secular melody. The oldest surviving piece of six-part music is the English [[rota (music)|rota]] ''[[Sumer is icumen in]]'' ({{circa|1240}}).<ref>[[Daniel Albright|Albright, Daniel]] (2004). ''Modernism and Music: An Anthology of Sources''. University of Chicago Press. {{ISBN|0-226-01267-0}}.</ref>