Music sampling is essentially using pieces of music to create new works of art. It is still done today, but it rose to prominence with the hip-hop scene in the 80s and 90s.
When an artist used a sample, it meant that they had found a part of another song that they wanted to incorporate into their own. For example, a hip-hop artist might sample an acoustic guitar recording, just taking a single chord progression from another song. They could then put drums over the acoustic guitar progression and then sing or rap over top of that. This creates a brand new song – but its base is still the original sample that was recorded by an entirely different artist, who wasn’t part of the project.
Is this still legal?
When sampling started, it was done because artists were legally allowed to use short portions of a song without having to pay royalties. So someone could sample 5 seconds of a song without worrying about the financial implications.
That has changed in the modern era. Samples need to be cleared, and artists who use samples without clearing them are in violation of intellectual property laws. The length of the song no longer matters. Just as it would be illegal for someone to take an entire track and record new lyrics over top of it, they can’t use a small sample without getting express permission in advance.
This can lead to some complicated disputes over intellectual property rights. Artists who are involved need to be aware of the legal options at their disposal.