The singer Alessandro Merlo has been confused with the composer Alessandro Romano; this confusion is maintained in RISM and in the Printed Sacred Music Database. According to Sherr (p. 464), Merlo's career "makes it nearly impossible for Merlo to be the same person as the composer Alessandro Romano, with whom he has been confused since the 19th century. Romano, who claimed to be a pupil of Willaert and Rore, published his first book of madrigals in 1554 (when Merlo was a choirboy in the Cappella Giulia)".
1534 (23-XII)—1539 Santiago de Compostela, niño de coro
1539 (29-IV)—1549 Capilla papal, cantor
1551—1585 Catedral de Palencia, maestro de capilla
As pointed out by José López-Calo and Cristina Diego Pacheco, documents related to the brothers Alonso, Pedro and Rodrigo Ordóñez often do not mention the first name, and thus it is difficult sometimes to ascertain their identity. In E-V 05 there are four polyphonic works attributed to Alonso Ordóñez and one to "Rº Ordóñez"; although the initial in the latter ascription has been interpreted as "Racionero" (to refer to Alonso Ordóñez), it is most likely that it refers to Rodrigo Ordóñez. There are no known works attributed to Pedro Ordóñez.
Regarding Pedro Ordóñez, singer in the Papal Chapel, it should be pointed out (as mentioned by Lopez-Calo), that Haberl stated (based on the Chapel's diaries) that Pedro Ordóñez died in Rome between 17 and 27 November 1549. However, presumably Pedro Ordóñez was named chapelmaster at Palencia Cathedral in 1551 and continued there until his death in 1585. A 1578 document at Palencia cathedral, though, indicates that Ordóñez had been there during forty years, but in 1538 he would have been in Rome, and thus this Ordóñez chapelmaster could be a different person than the Pedro Ordóñez in the Papal Chapel.
En el fol. 1 del Cantoral polifónico E-L 89 de la Catedral de León se lee: "Siendo Administrador / de Fábrica el Señor Don Lu / is Otazu, Reformó este / libro / Don Geronimo / Roman, Bajo de / Capilla de esta Sta. / Yglesia. Año de / 1828". (S. Rubio, Catálogo, p. 882).