This chapter highlights the function of and field surrounding the “the composer” as they have transformed through the ages in relation to privilege and law. It shows how the composer’s function can be seen as an assembly of labour functions granting an individual composer the right of credit for the work done in the eighteenth century that changed to a “genetic function” a century later which enabled composers to claim the music played on a certain occasion as “their” creation and thus entitling them to monetary compensation. The creative composer, according to this logic, implies yet another function, the production of the musical work that is the outcome of the composer’s creativity and that must be identifiable as such. Whereas since the nineteenth century the formal aspects of the notational score thus defined both the work (along lines spelled out by music critic Eduard Hanslick) and, by implication, its composer, this function is today practically fulfilled by digital algorithms that identify “fingerprints” of recorded sound. When the so-called content identity constitutes the original contribution of copyrighted music, one may legitimately ask the following question: what is a composer today?