The adaptation right gives the copyright owner the exclusive right to create derivative works. A derivative work or an adaptation is a new work based on an existing work. For example, if someone uses melodies from one composition in another composition, the adaptation right is implicated. The person using the piece from the existing composition needs permission from the original composer.
Music sampling is an example of a derivative use of older works. However, sampling is a controversial practice. Many samplers may argue that they do not need licenses to sample especially when they are sampling a very small portion of a recording and the original music cannot be recognized in the sampled work.
The few courts that have dealt with the issue have treated sampling of musical compositions different from sampling of sound recordings. While sampling very small portions of a composition has been held to be permissible, sampling of even small portions of sound recordings has not. However, the law in this area is far from settled. Samplers unable to obtain license are faced with three options: do not sample, assert fair use or claim that the use is de minimis use i.e. that the use is so small that it is permissible under the law. The test for de minimis use is whether the audience can identify the original work in the sampled work.