The "normal" orchestra ensemble—a body of strings supplemented by winds—and movements of particular rhythmic character were established by the late 1750s in Vienna. However, the length and weight of pieces was still set with some Baroque characteristics: individual movements still focused on one "affect" (musical mood) or had only one sharply contrasting middle section, and their length was not significantly greater than Baroque movements. There was not yet a clearly enunciated theory of how to compose in the new style. It was a moment ripe for a breakthrough.