On the final episode of The Late Show, Stephen Colbert discussed recent copyright enforcement efforts by Lee Mendelson Film Productions (“Mendelson”), owner of the musical catalog associated with the Peanuts franchise. During the segment, Colbert’s band began playing the familiar work “Linus and Lucy,” prompting the host to feign alarm that CBS might now face liability for using the very music he had just described as the subject of infringement claims.

The joke landed, but it also raised an interesting copyright question.

Colbert’s segment directly referenced the enforcement efforts, including a complaint filed against the Department of the Interior, and used the composition as part of the commentary itself. Although CBS and the rights holder ultimately reached a licensing agreement, reportedly with the proceeds earmarked for charity, the settlement introduced a potentially novel fair use argument.

Fair use has long provided a defense to copyright infringement for purposes such as criticism, comment, news reporting and parody. Courts frequently focus on whether the challenged use is “transformative” in the sense that it employs the original work for a different purpose than that for which it was created.

Here, the musical work was not used as background entertainment nor solely for its artistic appeal. Rather, it was played as the object of the joke. The segment’s entire premise depended on the audience recognizing the music that had become associated with the recent complaints. In that sense, the use arguably commented on both the work and the copyright owner’s efforts to control it.

Cases involving parody and criticism are somewhat analogous, where the use of at least some portion of the copyrighted work is necessary to evoke the target of the commentary. And courts have repeatedly recognized that effective criticism sometimes requires borrowing enough of the original to make the point.

However, unlike a traditional parody, the segment did not ridicule the song itself and was instead aimed at the consequences of copyright enforcement. If litigated, a court could have concluded that the music served primarily as a recognizable prop rather than as the subject of criticism. And given that the performance occurred on a commercial television program, Mendelson could have had arguments under the first (purpose of the use) and fourth (potential effect on the market) fair use factors.

The dispute therefore presented a question that copyright law has not squarely addressed: when a copyrighted work is used solely to comment on the copyright owner’s enforcement activities, is that use sufficiently transformative to qualify as fair use?

Since the matter was resolved, there will be no concrete answer soon, but it leaves copyright lawyers with yet another fascinating fair use question.