El líder de la hermandad era Juan Pedro López Sánchez, que también participó en la Misión M38 en 1949. Las fotos fueron tomadas por Lomax el 14 de diciembre de 1952 (disponibles en ACE).

En la caja de la cinta original, Lomax anota que el grupo estaba formado por "10 hombres que cantaban polifonía religiosa de oído" ("10 men singing religious polyphony by ear") e indica sus nombres:

10 men- Juan Pedro López Sánchez, the campana leader and bell ringer
F. Ferdinand Castejon (3rd)
Manuel Cortejón (5th)
Juan Hernández Castejón (2nd)
Antonio Pardo Serrano (base)
Juan López Valverde (2nd)
Camilo Nicolás Alazek (2nd)
Mariano García Avellan (2nd)
Francisco Bravo Reina (3rd)

En sus programas para la BBC, Lomax comenta la sesión de grabación con estos informantes: "[...] twelve leather faced peasants, with a handbell, chanting in honor of the Virgin [...] I turned the microphone slowly round the circle to underline each of the five parts. This was seventeenth century church polyphony... not from written sources, but a tradition handed down orally, in which these singers composed new songs when they liked. They could scarcely sign their names, these small, dark underfed workers in the orange groves, but they knew when everything was going well in the harmony; then the rocky face of their leader, who kept time with his hand bell, would crack into a smile".