The construction of Notre-Dame Cathedral in Paris, begun in 1163, was accompanied by the emergence of the Notre-Dame school of polyphonic music, centred on composers known as Léonin and Pérotin who flourished between roughly 1160 and 1230. Léonin compiled the Magnus Liber Organi, a collection of two-voice settings of plainchant for the liturgical year, representing the first substantial repertory of notated polyphonic music. This school developed the first systematic forms of rhythmic notation, solving a fundamental problem in transmitting musical performance to paper and making possible the later development of measured music throughout Europe.

The Notre-Dame school's development of rhythmic notation had consequences reaching far beyond sacred music. The ability to notate rhythm made possible the transmission of secular song — troubadour melodies, motet texts, rondeaux — in a reliable form, underpinning the preservation and spread of lyric poetry set to music across Europe. The motet form, which emerged from Notre-Dame polyphony, became a vehicle for vernacular love poetry and satirical texts as well as sacred music, blurring the boundary between lyric and musical composition.