The paper argues that contexts of interaction are structured in a way that coordinates part actions into normatively guided joint action without agents having common knowledge or mutual beliefs about intentions, beliefs, or commitments to part actions. The argument shows earlier analyses of joint action to be fundamentally flawed because they have not taken contextual influences on joint action properly into account. Specific completion of earlier analyses is proposed. It is concluded that attention to features distributed in context of interaction that signal expected part actions is sufficient for a set of part actions to qualify as a joint action.