According to Diccionario de la música Labor, p. 30, A singer named Francisco de Ajofrín was active in Toledo Cathedral in 1499. Perhaps this singer was the composer of the villancico Por serviros triste yo for three voices in the Cancionero Musical de Palacio (E-Mp II-1335).
11 songs from the Cancionero Musical de Palacio (E-Mp II-1335) are attributed to Alonso (A, Aº). According to Tess Knighton, there are five possible candidates with that first name:Alonso de Alba, Alfonso Hernández de Tordesillas, Alonso de Toro, Alonso de Córdoba and Alonso de Mondéjar.
According to Diccionario de la Música Española e Hispanoamericana pg. 27 Vol 5. Mitjana identified Diego Fernández as the author of three-voice villancico located in the Cancionero Musical de Palacio (E-Mp II-1335) De ser malcasada and Tres moricas me enamoran. However, Higinio Anglès rejected Mitjana's hypothesis.