Earlier quoted context omitted.
You need to get permission from the copyright holder, which has gotten substantially more expensive over the years. Hip hop tracks back in the 80s and early 90s used to contain loads of different samples all mashed together, but it slowed down a bit after people started suing. Nowadays sampling isn't quite as popular, and sampled tracks don't usually use more than one or two samples. The rapper Fabolous had a hit son…
For non-commercial use, can an artist sample without legal threat? For example, if an artist is just posting 80s style tracks with dozens of uncleared samples on their website free for their fans to download, doesn't fair use allow for it?
Also free-gratis isn't co-terminous with non-commercial as - for example - giving away a competing product is a commercial activity. Also moral rights can arguably be harmed by sampling ... and then you've got parody exceptions ... it's nuance all the way down.