The metrical foot has a long pedigree as a theoretical device in generative phonology (Liberman & Prince, 1977; Halle & Vergnaud, 1978; Selkirk, 1980; Hammond, 1984; Halle & Vergnaud, 1987; Idsardi, 1992; Hayes, 1995). While the motivations for foot structure are typically studied in terms of stress, this paper provides evidence from the principles of formal language theory (Chomsky, 1956; Hopcroft & Ullman, 1979) for foot-based analyses of non-stress processes. Though use of foot structure in these analyses is not novel (see Gonzalez (2018) for an overview) this paper contributes a precise characterization of what is at stake in terms of the computation of these processes when foot structure is present versus when it is not...