One of the most difficult issues in the study of the ballet d'action has emerged tangentially from time to time in this book, but deserves to be met head on: what should we make of the remarkable phenomenon that was the performance programme? This is likely to be one of the first questions that anyone studying the ballet d'action will ask themselves, since these programmes are by far the most abundant vestige of an ephemeral art which has, by nature, left little trace. It is unlikely, however, to be the first question that we are able to answer. Even if these performance programmes are easily accessible in libraries all over Europe, it is difficult to know how to interpret them. They offer little technical information on choreography or staging, and instead are mostly devoted to recounting the version of the mythological, historical, literary, or sometimes original story on which the performance was based. It is safe to assume that they correspond in some way to the stage action, but the nature of the correspondence is hard to judge.