In virtual environments, the control of numerous entities in multiple dimensions can be difficult and tedious. In this paper, we present a system for synthesizing and recognizing aggregate movements in a virtual environment with a high-level (natural language) interface. The principal com- ponents include: an interactive interface for aggregate con- trol based on a collection of parameters extending an exist- ing movement quality model, a feature analysis of aggregate motion verbs, recognizers to detect occurrences of features in a collection of simulated entities, and a clustering algorithm that determines subgroups. Results based on simulations and a sample instruction application are shown.