' s ▁work ▁was ▁well ▁before ▁this . ▁Philip ▁appears ▁to ▁have ▁written ▁a ▁number ▁of ▁po ems ▁with ▁the ▁intention ▁of ▁them ▁being ▁set ▁to ▁music ▁by ▁P é rot in , ▁and ▁with ▁him ▁is ▁given ▁credit ▁for ▁the ▁development ▁of ▁the ▁mot et . ▁ ▁List ▁of ▁works ▁▁ ▁An onymous ▁IV ▁identified ▁seven ▁works , ▁that ▁he ▁pres umably ▁considered ▁worthy ▁of ▁sing ling ▁out , ▁and ▁these ▁represent ▁the ▁only ▁direct ▁att ribution . ▁Sub sequ ent ▁authors ▁have ▁attributed ▁works ▁on ▁sty list ic ▁and ▁chron ological ▁grounds . ▁These ▁include ▁Friedrich ▁Ludwig ▁( 1 9 1 0 ), ▁Heinrich ▁Hus mann ▁( 1 9 4 0 ), ▁Hans ▁T isch ler ▁( 1 9 5 0 ) ▁and ▁Eth el ▁Th ur ston ▁( 1 9 7 0 ). ▁Hus mann ▁added ▁an ▁additional ▁nine ▁three - part ▁org ana , ▁and ▁five ▁cla us ula ▁to ▁which ▁Ludwig ▁added ▁numerous ▁other ▁cla us ula . ▁Other ▁authors ▁have ▁attributed ▁all ▁the ▁three - part ▁org ana ▁in ▁the ▁Magn us ▁Liber ▁to ▁P é rot in , ▁which ▁is ▁unlikely . ▁Nevertheless , ▁two ▁of ▁the ▁only ▁three ▁known ▁four - part ▁org ana ▁can ▁be ▁attributed ▁to ▁him . ▁ ▁Key : ▁An onymous ▁IV ▁( A ), ▁Johannes ▁de ▁Gar land ia ▁( G ), ▁T isch ler ▁( T i ), ▁Th ur ston ▁( Th ), ▁Hus mann ▁( H ). ▁Num bers ▁refer ▁to ▁fol ios ▁in ▁the ▁F ▁manuscript