This paper presents a distributed control approach to legged locomotion that constructs behavior on-line by activating combinations of reusable feedback control laws drawn from a control basis. Sequences of such controller activations result in flexible aperiodic step sequences based on local sensory information. Different tasks are achieved by varying the composition functions over the same basis controllers, rather than by geometric planning of leg placements or the design of new task-specific behaviors. In addition, the device-independent nature of the control basis allows its generalization not only over task domains, but also over different hardware platforms. To show the applicability of this approach, a control basis and two generic control gaits for four-legged walking are introduced and tested on an even terrain walking task in an unknown environment.