I used to be a music lawyer and I was a bit of an authority (for a while) on sampling and sample clearance in the early ‘90’s. Then I ran a bunch of dance labels and worked with a lot of electronic artists. I have cleared a lot of samples but I have released way more records with samples in them that we didn’t bother to clear. Why? Because we thought that no-one would notice that we’d used their music - these were generally small specialist underground records - and that if they did, we would be able to agree something after the event, if the need ever arose. The reality is that it was too much bother and too expensive to try and clear a sample of an obscure and hard to find piece of music or of a snippet of a big successful tune when you knew that your record was going to sell just a few thousand copies - i.e. we felt at the time that the risk was well worth it. And hundreds of thousands of records have been released with uncleared samples in them.