There has been significant angst in copyfighting circles about a US court of appeal panel decision in the case of Bridgeport Music, Inc. v. Dimension Films. They decided that sampling three notes constituted copyright infringement. Respected intellectual property practioner and scholar, William Patry, is damning in his analysis of the decision.
"The original panel opinion, as well as Friday's, are controversial, for at least two reasons. First, the panel adopts a different approach to infringement of a musical composition embodied in a phonorecord than for infringement of the sound recording embodied in that same phonorecord; second, the difference lies in the lack of any requirement of even a de mininis taking for sound recordings. (While finding that a sampling of three notes was infringement, the court demurred on whether sampling of one note would be. I fail to see any basis in the court's reasoning for excusing the taking of one note when three is infringement)...
It is true, as the court stated that a bright line test, one which says "Get a license or do not sample" provides "ease of enforcement." But that is equally true of all other subject matter: you want to parody a work, get a license; you want to write a book review, get a license; you want to quote three words from a poem in a movie, get a license.
The court believed that samplers don't take accidentally, but that is true of all my examples, and the more than de minimis copying requirement for substantial similarity has never been based on unconsicious copying. Nor is there anything special about copying by sampling versus copying by incorporating three notes from a musical composition into another musical composition or into a phonorecord. The court also believed that even three sampled notes have value. Ditto other copying, but whether the portion copied has value has never been the test for infringement (although it is relevant at the much later fair use stage).
Bridgeport is policy making wrapped up in a truncated view of law and economics, shorn of analysis of all the public interest factors and harm to derivative creators that nuanced exponents, such as Judge Posner, engage in."