In later periods genres proliferated and developed in response to changes in audiences and creators. Genre became a dynamic tool to help the public make sense out of unpredictable art. Given that art is often a response to a social state, in that people write/paint/sing/dance about what they know about, the use of genre as a tool must be able to adapt to changing meanings. Proponents argue that the genius of an effective genre piece is in the variation, recombination, and evolution of the codes.