This thesis contributes analyses of two works by Mexican composers: Rayo nocturnal (1989) by Victor Rasgado (b. 1959), and the Cuarteto da do (1988) by Juan Trigos (b. 1965). Although composed according to structuralist principles, a postmodern interpretation is offered. The analytical method applied is based on Allen Forte's set theory, including rhythmic and timbral dimensions that are integral to the conceptions of these works. A survey of modernism and postmodernism in twentieth-century Mexico serves to place these works in their cultural context.