he term imitatio is a fairly recent addition to the modern scholarly vocabulary used to discuss late Medieval and Renaissance music. Introduced just over twenty-five years ago by Lewis Lockwood in his important article on parody, it was given a considerably broader interpretation in 1982, in a rich and stimulating article on theories of imitation by Howard Brown.' Still other views were presented shortly thereafter by Leeman Perkins in 1984 and by J. Peter Burkholder in 1985 in two other provocative articles, and the term has since appeared with some regularity in discussions of musical compositions based on borrowed models.2 Despite the ready