Léonin (also Leoninus, Leonius, Leo) (fl. 1150s — d. ? 1201) was the first known significant composer of polyphonic organum. He was probably French, probably lived and worked in Paris at the Notre Dame Cathedral and was the earliest member of the Notre Dame school of polyphony and the ars antiqua style who is known by name.
Philippe de Vitry (31 October 1291 – 9 June 1361)
(c. 1300 – April 1377) was a medieval French poet and composer. He is one of the earliest composers on whom significant biographical information is available.
The Notre Dame school or the Notre Dame School of Polyphony refers to the group of composers working at or near the Notre Dame Cathedral in Paris from about 1160 to 1250, along with the music they produced.
The only composers whose names have come down to us from this time are Léonin and Pérotin. Both were mentioned by an anonymous English student, known as Anonymous IV, who was either working or studying at Notre Dame later in the 13th century. In addition to naming the two composers as "the best composers of organum," and specifying that they compiled the big book of organum known as the Magnus Liber Organi, he provides a few tantalizing bits of information on the music and the principles involved in its composition. Pérotin is the first composer of organum quadruplum — four-voice polyphony — at least the first composer whose music has survived, since complete survivals of notated music from this time are scarce.
Pérotin (fl. c. 1200), also called Perotin the Great, was a European composer, believed to be French, who lived around the end of the 12th and beginning of the 13th century. He was the most famous member of the Notre Dame school of polyphony and the ars antiqua style. He was one of very few composers of his day whose name has been preserved, and can be reliably attached to individual compositions; this is due to the testimony of an anonymous English student at Notre Dame known as Anonymous IV, who wrote about him and his predecessor Léonin.
Jacopo da Bologna (fl. 1340 – c. 1386) was an Italian composer of the Trecento, the period sometimes known as the Italian ars nova. He was one of the first composers of this group
He concentrated mainly on madrigals,