LEONINUS. — Composer of the Ars antiqua, active in the 12th century (ca. 1160–80) in Paris, at the church of Beatae Mariae Virginis, later called Notre-Dame.
The most important historical source of information about L. is provided by a 13th-century writer (the Anonymous IV of C. E. H. Coussemaker: Scriptores de musica medii aevi, I, Paris 1864, pp. 327, 341), who calls him optimus organista, that is, a composer of organa dupla, in which the upper voice had a melismatic character, while the lower voice (tenor) “held” the melody with long, “pedal-like” notes.
A collection of approximately 90 of his organa (two-part compositions for the entire liturgical cycle, entitled Magnus liber organi de graduali et antiphonario pro servitio divino multiplicando) remained in use until the time of his great successor Perotinus, who revised it and added his own works.
L. is the first great musical figure of the new era, constituting the transition between the rhythmically free style of st. Martial of Limoges and the strictly rhythmic style, according to the rhythmic modes, which would later be employed by Perotinus. Among the compositions attributed to L. by critics are: Haec dies, Crucifixum in carne laudate, and Deum time, pieces that have also been recorded on phonograph records.