THE KNOWN FACTS OF ESQUIVEL'S LIFE ARE FEW: we do not even know the date of his birth. The amount of contemporary documentary evidence available to us is slender and sometimes conflicting, and has led to much speculation on the part of later scholars. In an attempt to unravel the facts of Esquivel's life we shall first examine the documentary evidence that does remain and then study the contributions of recent scholars who have attempted to shed further light on the composer's life and work.

During the sixteenth century, detailed records were kept of cathedral chapter meetings. The minutiae of day-to-day decisions made by the chapter on such matters as the fabric of the building, the employment of musicians and so forth were recorded in the capitular acts (actas capitulares); these make fascinating reading as well being a valuable source of information for later historians. Thus it is to the actas capitulares of the cathedral of Ciudad Rodrigo, Esquivel's birthplace, that we turn for the first piece of documentary evidence.

There, in an isolated reference for 22 October 1568, it is recorded that Juan de Esquivel is received as a mozo de coro. The term mozo de coro was usually applied to the altar boys as distinct from seises – members of the choir who were trained in polyphony – although, as Samuel Rubio has noted, not all capitular acts make a clear distinction between the two groups; sometimes the term mozo de coro is applied indiscriminately to both groups. In the absence of any clear interpretation of this terminology we cannot be sure to which group Esquivel belonged. This is unfortunate since it would help to shed some light on his age when admitted to the service of the cathedral.

The seises were young boys, frequently six in number, hence their name. They were chosen by the maestro de capilla and admitted to cathedral service by the chapter by virtue of their vocal ability. Having been admitted, they usually lived with the maestro who had the additional task of providing for their physical needs as well as being responsible for their musical training.