Figure 0. Multiple Bouncing Spheres interfaces visualized from a centralized viewpoint. Each human player manipulates spheres over a portion of the squares. The ensemble is synchronized by computer. Emergence is the formation of complex patterns from simpler rules or systems. This paper motivates and describes new graphical interfaces for controlling sound designed for strongly-timed, collaborative computer music ensembles. While the interfaces are themselves minimal and often limiting, the overall collaboration can produce results novel beyond the simple sum of the components – leveraging the very uniqueness of an ensemble: its strength in numbers. The interfaces are human-controlled and machine-synchronized across a dozen or more computers. Group control, as well as sound synthesis mapping at each endpoint, can be programmed quickly and even on-the-fly, providing a second channel of real-time control. We show examples of these interfaces as interchangeable plug-ins for the Audicle environment, and also document how they are used in a laptop ensemble. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Nime’06, June 4-8, 2006, Paris, France. Copyright remains with the author(s).