The cantus firmus is the 18th verse of an 11th-century prosa for the Feast of the Assumption, 'Aurea virga primae matris Evae'
A-Wn-ms-Mus.Hs.15495: Composer name in ms = 'Bruhier' / Kyrie I: 'Tenor' and 'Bassus': 'Mediatrix nostra' (red ink) / Et in terra: Canon inscription upside down at the end of the written voice: 'Reverte in requie[m] tua[m] / Domine deus: 'Tenor tacet' / Patrem: With textless 'secundus discantus' / Deum de deo: 'Tenor 2': 'In subdyapason' / Confiteor: With textless [Superius2] / Pleni: 'Tenor' and 'Bassus': 'Duo' / Benedictus: 'Tenor tacet' / 'Osanna ut supra' / Agnus I: 'Bassus': 'Canon' and 'In dyapenthe' / Agnus dei - Dona nobis: 'Tenor in dyapason'
