A facsimile of a previously unpublished musical manuscript. Among the major composers of the Portuguese "Golden Age," Pedro de Cristo (c.1550–1618) is at present the least familiar to scholars and performers. This situation is largely due to the fact that his music was not published during his lifetime, but is preserved rather in manuscripts originating (for the most part) at the Monastery of Santa Cruz in Coimbra, where he spent most of his life. The present work is an edition of the contents on one of these manuscripts — MM 33 in Coimbra University Library — which was copied by Pedro de Cristo himself towards the end of the sixteenth-century. It is an invaluable source of authoritative readings of his music: principally Latin motets for four or five voices.