The boundary between copyright and sampling lies in legality and permission. Copyright protects original works, requiring permission or licenses for sampling. Fair use may allow limited sampling for transformative purposes like commentary or parody, but courts assess factors like purpose, amount used, and market impact. Unauthorized sampling risks infringement lawsuits. Always seek legal advice or clearance for commercial use.Related websites:  https://www.copyright.gov  
https://www.wipo.int/copyright/en/  
https://fairuse.stanford.edu