[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The goals of my study are to research the plainsong mass for the dead, to learn from scores of instrumental requiems, and to compose an instrumental requiem that fulfills the requirements of my master's degree in music composition. In studying the plainsong masses of the requiem I will find some melodic materials that will be suitable themes and cells in my composition. In observing nonlinguistic requiems, I hope to gain some insights from the composters about writing strategies, specifically dealing with the integration of plainsong melodies. This study is important to me because I intend to use this research as a beginning to further studies of the music of the Missa p...