Know those records that you insert into a vinyl record player? Basically those, but pirated since a real one costs money when you purchase them at official music retailers. It involves the process of obtaining a legal copy then using wax molds (to recreate a record) and specialized tools (prevent quality loss) duplicating the record. (Also, “Bone Music” existed in the Soviet Union by printing music by using x-ray films).
I’m old enough to remember when owning record players was the norm, but I don’t remember anyone pirating anything - they weren’t considered expensive. Cassette piracy in the 80s and early 90s - now that I do remember.
However, it certainly was a thing. In the USSR they figured out how to do it on discarded x-rays - which, I have to admit, is the most punk thing ever.