The Longhouse Iroquois of Southern Ontario and New York State are carriers today of an ancient tradition of political and religious oratory, one strand of which is a set of speeches, chants and songs associated with the calendrical round of ceremonies. Among these are four rituals based on a graded hierarchy of "spirit forces" -- from the animals and plants on earth to the celestial bodies in the sky, to completely ethereal beings beyond. The study, based on analysis of 17 transcribed and translated versions of these rituals from seven speakers representing four longhouses and two languages (Cayugo and Seneca), focuses on three interrelated points: the hierarchic rituals reflect the Iroquois conceptualization of the cosmos; they reveal two kinds of variation, one associated with differences in function among the four types, the other associated with stylistic differences for speakers belonging to different local traditions; and variation in performance is linked to the process of oral composition itself.