0 1 , ▁since ▁for ▁most ▁of ▁ 1 2 0 0 ▁France ▁lay ▁under ▁an ▁inter dict ▁of ▁Pope ▁In noc ent ▁III ▁which ▁suppress ed ▁the ▁celebr ation ▁of ▁church ▁services . ▁Hans ▁T isch ler ▁dates ▁the ▁revision ▁of ▁the ▁Magn us ▁Liber ▁to ▁around ▁ 1 1 8 0 / 9 0 . ▁Between ▁the ▁accounts ▁of ▁An onymous ▁IV , ▁the ▁epis cop al ▁ed ict s ▁and ▁the ▁arrang ements ▁in ▁the ▁Magn us ▁liber , ▁the ▁key ▁compos itions ▁appear ▁to ▁be ▁cor ro bor ated ▁and ▁assigned ▁to ▁this ▁period . ▁ ▁P é rot in ▁composed ▁music ▁to ▁at ▁least ▁five ▁of ▁the ▁po ems ▁of ▁the ▁Chan cell or ▁of ▁the ▁c athedral , ▁Philippe ▁le ▁Chan cel ier ▁( Ph il ip ▁the ▁Chan cell or ). ▁Philip , ▁also ▁a ▁canon ▁there , ▁held ▁that ▁title ▁at ▁the ▁c athedral ▁from ▁ 1 2 1 8 ▁till ▁his ▁death ▁in ▁ 1 2 3 6 , ▁suggesting ▁a ▁possible ▁later ▁date ▁for ▁P é rot in ' s ▁setting ▁of ▁the ▁former ' s ▁Be ata ▁vis cera ▁( ca . ▁ 1 2 2 0 ), ▁or ▁at ▁least ▁a ▁termin us ▁ante ▁qu em . ▁O thers ▁believe ▁this ▁poem ▁was ▁written ▁much ▁earlier , ▁and ▁hence ▁place ▁P é rot in ' s ▁death ▁as ▁no ▁later ▁than ▁ 1 2 0 5 , ▁the ▁bishop ' s ▁ed ict s ▁imp lying ▁that ▁P é rot in