Léonin

Léonin (fl. c. 1163-1200), French singer and composer associated with early organum and the development of polyphony. His identity is uncertain, but the treatise known as Anonymous IV (c. 1280) describes a Magister Leoninus as “the greatest composer of organum” at the Parisian church of the Blessed Virgin, now assumed to be the then-new Cathedral of Notre Dame. Léonin is credited in Anonymous IV with the compilation of a Magnus Liber Organi (Great Book of Organum), which contains two-part vocal settings of the solo sections of the graduals, alleluias, and responsories for augmenting the liturgy on special feast days. As none of the manuscripts containing the music of the Magnus Liber Organi name a composer, Léonin was perhaps one of a group of talented singers who set down what had evolved as an improvisatory art. The development of the modal notation system at the end of the 12th century ensured the wide currency and influence both of the Magnus Liber Organi and of its later reworking by Pérotin. The organa attributed to Léonin are of two types: either the plainsong tenor in long sustained notes supports the florid and virtuoso upper voice as in the early organum style of St Martial of Limoges, or the two voices move at roughly the same rate in the more modern discant style that was to form the basis of medieval music.