Person

Collegiate church of Saint-Saveur, Blois, 1449-1450
"Maistre Guillaume le Rouge" is paid in 1450 as "maistre des enffens de cuer" of the collegiate church of Saint-Sauveur, Blois, for his participation in the votive services of the church of that year (account of the church for the year 1449-1450 in F-Pnm, fr. 6215, f. 29v: liste des anniversaires gagnés par les chapelains et mareliers: "Maistre Guillaume Le Rouge, maistre des enffens de cuer 32s 6d pour ce. <add.: n. q. fuit solut. per caplm>"; the latin addendum seems to mean that "nothing of this has been paid by the chapter", as is confirmed by the fact that the sum is note recorded in the column on the right side of the page]); the master of children is also mentionned, unnamed, on f. 19; these mentions have been made public by Rob Wegman in a Facebook post on 13/07/2015).

Court chapel of duke Charles d'Orléans, 1451-1465
He then appeared amongst the singer of the court chapel of duke Charles d’Orléans, most of the time located in Blois, and is named in all known chapel lists until the duke's death and the dismantlement of the chapel in 1465 ("several dozens" of available lists are mentionned in Higgins 1987, p. 251 and 306, four of which, for the years 1464 and 1465, have been published in Higgins 2009, p. 181-182; a few other lists had already been published in Laborde 1853, III, p. 357, 372-373, and Champion 1911, p. 389)

Composer
Two works by ascribed to him in 15th-c. manuscript: a three-voice Missa ‘So ys emprentid’ (I-TRmp 90, ‘W. de Rouge’; Rvat S Pietro B80, anon.), on Frye's song, and a three-voice virelai, Se je fayz deuil (US-NHub 91, ‘G. le Rouge’; D-Mbs Cgm 810, anon.) He is also mentionned by the theorist Johannes Tinctoris as the composer of a Missa Mon cuer pleure, now lost (Proportionale: [47] Et alii eodem signo temporis imperfecti et prolationis maioris subsesquitertiam, ut hic: [example] Quod licet faciant Lerouge et Puyllois in Missis Mon cuer pleure et in quodam "Et in terra" plagalis autenti triti irregularis tamen est intolerabile").