Santa Eulalia M. Md. 7, dated January 20, 1600, is part of the San Miguel Acatán Repertory, which originated in the northwestern highlands of Guatemala and is presently owned by the Lilly Library of Indiana University. The manuscript contains thirty-four four-part songs and dances, two thirds of which are villancicos for Christmas, Easter, the Eucharist, and the feasts of All Saints and St. Michael. The remaining third consists of Latin biblical texts in either fabordón or contrapuntal settings, three pieces with Náhuatl texts, and an instrumental pavana. The thesis contains a modern edition of Santa Eulalia M. Md. 7 with critical notes and commentary, a comparison of the pieces with villancicos and fabordones of European origin, and a survey of several aspects of Mayan culture.