Having defined drama and music, courts set out weighing the relative value of non-ontological aspects of performances that might nonetheless be valuable. Courts recognized, first, that affect---arousing emotions in an audience---was central to performances, but refused to allow that affect to be solely erotic desire, as in a case involving The Black Crook. Likewise, while acknowledging the import of actors’ contributions to a comedy’s success, courts refused to declare such alterations of a script part of the legally protected “dramatic composition.” Adaptations---both from novel to play and from France to England---proved a further difficulty in the period, as courts struggled to define the difference between simple translations between media or countries and more subtle adaptations of similar subject matter. In litigation about Our American Cousin, courts questioned the premise of performance rights, suggesting that performance ontologically invited memorization and repetition. Finally, a late-nineteenth-century case reveals a legal system satisfied with its definitions of performance rights and comfortable defining the value of performance in solely economic terms.