Suppose you owned a piece of land and took no legal action while others used it for more than two decades. When you (or your successor) eventually tried to evict those users, would you prevail? For centuries, the doctrines of adverse possession and easements by prescription have stood in the way of such long-delayed action. These doctrines rest on a notoriously mixed bag of rationales, including protecting the expectations of users, who may or may not have been acting in good faith; promoting productive use of land; keeping title free of complications that may hinder transfer and investment; and obviating the need to decide cases on thin, stale evidence of ownership claims. But the doctrines themselves have remained a remarkably durable part of land law.

Copyright law has never had similar doctrines (nor has patent law). As long as the term of copyright remained relatively short, it arguably had little need for them. Copyrighted works were going to enter the public domain soon anyway -- after, at most, 28 or 42 or 56 years -- and they would enter the public domain even sooner if copyright holders didn't assert their continuing interest in the works by filing a renewal registration after 14 or 28 years. Now, however, copyright can last for 120 years or more, and has no renewal requirements. Thus, it is possible for a copyright owner to neglect to enforce copyright for decades, and then return and reassert ownership for decades more.

The history of "Happy Birthday to You" gives us a glimpse of what can happen when long copyright has no adverse-possession-like doctrine. The song was distributed widely for about 20 years from the early 1910s to the early 1930s without any permission from or enforcement by the Hill sisters or their publishers. It was during that period -- a period when the song was de facto in the public domain -- that it became THE standard birthday song in the United States. It is even conceivable that the lack of copyright enforcement contributed to the song's assumption of its central place in American culture. Then the putative copyright owners resurfaced and started claiming royalties, not for another decade or so until 1949, but, it now appears, for another 95 years until 2030.

The copyright community has started discussing the related and partially overlapping problem of "orphan works," but so far there's been no legislative progress on that front. The doctrine of adverse possession was actually a judicial creation, piggybacking on top of statutes of limitations. The copyright statute of limitations, however, is so short -- 3 years -- that it is unlikely that judges will ever read doctrines of adverse possession or prescription into it. The result is that copyright will likely increasingly face all of the problems -- clashing expectations, clouded title, stale evidence, use-inhibiting uncertainty -- that land ownership would have without those doctrines.

One comment earlier this week noted the evidentiary problems that arise as works under copyright get older and older. Some of those are inevitable. Others could be avoided with better Copyright Office recordkeeping policy, which has not kept up with the increasing copyright term. As I detail in my article, the Copyright Office has maintained a policy of discarding much correspondence and many deposits after a decade or two. In addition, there has never been a way for the public to learn when the Copyright Office has denied registration of a work, unless the dispute gets into the courts, because only successful registrations are assigned searchable numbers. I heard a rumor that there had been an unsuccessful attempt to register the "new" melody of "Happy Birthday to You," different from the melody of "Good Morning to All" only in that the quarter note to which "Good" was sung was split into two eighth notes to accommodate the word "Happy." The rumor is probably false, but since there's no way to search denied registrations . . . who knows?

With that, I'll conclude my series of posts about "the World's Most Popular Song." Thanks again to Eugene for giving me this opportunity, and to all of you who responded for your comments and discussion.