There is no biographical information about Gaspar de Aguilar, author of the treatise Arte de principios de canto llano, nuevamente enmendado y corregido por Gaspar de Aguilar, con otras muchas reglas necesarias para perfectamente cantar. Dirigido al muy ilustre señor, don Pedro Manrique, obispo de Ciudad Rodrigo y capellán mayor de la capilla de los Reyes Nuevos de la santa iglesia de Toledo (from the early 16th century, without date and place of publication), of which a unique copy is found at the Biblioteca Colombina in Seville.
Polyphonic works atrributed to "Aguilar" in El Escorial and the Capilla Real in Granada are most likely by Francisco Aguilar (I).
Title and date of treatise:
Arte de principios de canto llano (Gaspar de Aguilar, early 16th c.)
Bernadette Nelson (2001), annotated: "He was an Augustinian canon at the priory od S Cruz, Coimbra, where he received his habit on 12 September 1609, and he was also mestre di capela at the monastery of S Vicente de Fora, Lisbon, the sister house of S Cruz. He was highly respected both as a practical musician and as a theorist".