This guide presents a detailed discussion of various aspects of historical performance practice, especially as they relate to liturgical polyphony of the Renaissance. The author considers such issues as timbre, tempo, and rhythm, the makeup of the ensemble, articulation, ornamentation, pitch and tuning, and interpretive goals—issues in which pre-modern choral technique and modern practice have often distinctively diverged. Musicological and performance perspectives are both drawn upon to address these issues in a manner that is both documentary as well as practical. This study will be of interest to musicians who specialize in early music, but it is also particularly addressed to conductors and singers who come to early music from the mainstream and perform it in that context. Mainstream choral conductors faced with the need to develop expression in multiple styles across a broad repertory will come to find the interpretation of historical style a congenial ally.