The book’s final chapter focuses squarely on interpretive authenticity’s place in our practice of work performance. It is pointed out, first, that interpretive authenticity is a performance value and, second, that, no less than score compliance, it is valued for its own sake. Crucially, however, it is argued, in addition, that interpretive authenticity is the practice of work performance’s most fundamental value. This is because interpretive authenticity, and not score compliance authenticity, is the practice’s constitutive norm: that is, it belongs to the nature of the activity of performing works of Western classical music that performances both ought to maximize, and are trying to maximize, interpretive authenticity. The chapter gives examples in which the norms of interpretive authenticity and score compliance authenticity conflict with each other. It follows from the proposed account of the practice’s normative profile that such conflict should be resolved by sacrificing textual fidelity for the sake of increasing a performance’s interpretive authenticity.