With the exception of a satiric comedy, Il Candelajo, all the works of this period are devoted to this logic - De Umbris Idearum, Ars Memoriae, De cornpendiosa architecture et complemento artis Lullii, and Cantus Circaeus.
It is highly doubtful, however, whether he had anything to do either with the Antiphonary or with the invention or revival of the cantus planes; it is certain that he was not the founder of the Roman singing-school, though he may have interested himself in its endowment and extension.
The Gloria takes the plainchant Ave Maria as a cantus firmus and the Sanctus uses the plainchant Salve Regina.
