The mass and the motet are the most important musical components of the Catholic liturgy. The development of vocal polyphony in the Medieval Period culminated in the perfection of these forms in the sixteenth century. The purpose of this thesis is to give an account of the development of religious monody and polyphony that led to the inception of the motet in the early part of the thirteenth century; to show the development of the motet through the sixteenth century; to give a more detailed analysis of the style of Palestrina; and to emphasize the analysis with a stylistic examination of a Palestrina motet.