early 15th century) was a French composer in the ars subtilior style of late medieval music.

Virtually nothing is known of Cordier's life, aside from an inscription on one of his works which indicates he was born in Rheims and had a Master of Arts.

Such an approach is thought to have inspired later composers, ranging from Gilles Binchois to Karlheinz Stockhausen.

")[5] Ten of Cordier's secular pieces survive, most of which are rondeaux: Two of the composer's chansons are in the Chantilly Manuscript and are well-known examples of eye music: Many commentators have speculated that Cordier's unique and experimental notation inspired certain notation by later composers, such that in as Refrain by Karlheinz Stockhausen,[10] and Gilles Binchois's Je ne pouroye.

[11] Cordier's work was among the earliest Western compositions to include performance instructions to explain how to use the specialized notation.