This paper presents a multiple-agent architecture created in Max/ MSP that generates polyphonic rhythmic patterns which continuously evolve and develop in a musically intelligent manner. Agent-based software offers a new method for real-time composition that allows for complex interactions between individual voices while requiring very little user interaction or supervision. The system described, Kinetic Engine is an environment in which networked computers, using individual software agents, emulate drummers improvising within a percussion ensemble. Player agents assume roles and personalities within the ensemble, and communicate with one another to create complex rhythmic interactions. The software has been premiered in a recent work, Drum Circle, which is briefly described.