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Vanderbilt Law Review

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copyright, prior art, intellectual property, expert witnesses


Civil Law | Intellectual Property Law | Law


Patent law and copyright law are widely understood to diverge in how they approach prior art, the universe of information that already existed before a particular innovation’s development. For patents, prior art is paramount. An invention can’t be patented unless it is both novel and nonobvious when viewed against the backdrop of all the earlier inventions that paved the way. But for copyrights, prior art is supposed to be virtually irrelevant. Black-letter copyright doctrine doesn’t care if a creative work happens to resemble its predecessors, only that it isn’t actually copied from them. In principle, then, outside of the narrow question of whether someone might have drawn from a preexisting third-party source, copyright infringement disputes would seem to have little doctrinal use for prior art.

But that principle turns out to be missing a big part of what’s actually going on in copyright litigation today. In this Article, we identify a surprising trend: parties in cases involving music are increasingly discussing anticipatory earlier works, and judges are increasingly holding it against them if they don’t. The concept of prior art, once for inventors only, is now for authors, too.

A major cause for this change, we argue, is the influence of a small cadre of expert witnesses. We interviewed several of the most active experts in music copyright disputes, and we analyzed dozens of reports that they have filed over the last two decades. Our data revealed a group that has been focused on authorial prior art since well before the courts were. These experts’ professional self-understanding, moreover, diverges sharply from the traditionally limited role that experts are supposed to play in evaluating copyright infringement. They view prior art research as a major part of their job. And for many of them, that research is important not just because it can sift between copying and independent creation, but also because it informs their normative view of what expression deserves legal exclusivity in the first place. Because of this expert community, prior art isn’t just for patents anymore.



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