It doesn't. Sampling is technically illegal. However the bootleg market is often too small to go noticed and larger artists get authorisation before sampling (or at the very least - releasing).
You do often see some artists turn a blind eye to sampling though. Particularly dance artists because many of them know their entire genre exists of the back of sampling. So it would be counterproductive / hypocritical for them to chase after royalties
Sample clearance is generally not required if:
- You are just using the sampled music at home.
- You are using the sample in live shows. This is because,
usually, you are not making copies and the owner of the venue
pays the blanket license fees to performing rights organizations
such as Broadcast Music Incorporated (BMI) or American Society of
Composers, Authors, and Publishers (ASCAP).
- You plan to distribute copies to the public but meet one of the
following: (1) an average listener would not notice the similarities
between your end product and the sample, or (2) your use of the
sample falls under the "fair use" doctrine. For more information on
these, see "Defending a Lack of Sample Clearance," below.
You do often see some artists turn a blind eye to sampling though. Particularly dance artists because many of them know their entire genre exists of the back of sampling. So it would be counterproductive / hypocritical for them to chase after royalties