Abstract: An agitator capable of generating complex mixing motions is described. In some embodiments, an agitator in accordance with the present teachings includes a movable assembly that is suspended, via several resilient supports, from a frame. The movable assembly receives a vessel containing a material(s) to be agitated. The movable assembly advantageously includes spaced upper and lower plates having a rotatably-supported member disposed therebetween. The mass of the rotatably-supported member is asymmetrically distributed about its rotational axis. A drive force, such as a directed air flow, which may be used in conjunction with a belt drive mechanism, causes the rotatably-supported member to rotate. Due to the asymmetric mass distribution of the rotatably-supported member, force is non-uniformly applied to resilient supports such that, at any given time, some of such resilient supports are subjected to a compressive force while other resilient supports are placed under tension.