I think you're discounting the cost of pre-network human communication a bit too much. Before computers, it was nearly impossible to copy a musical song from o

I think you're discounting the cost of pre-network human communication a bit too much. Before computers, it was nearly impossible to copy a musical song from one person to another faster than the time it took to perform it. And to go that fast, you needed someone trained to perform it well enough (cheap, but not free) and someone trained to memorize it by ear in one take (expensive). To do it more slowly, with more repetitions, you still needed someone that could perform what they had learned, which was cheap, but not free. The cost of connecting the teacher with the learner was likewise not free. They had to be in the same place, physically. They might meet up, learn each other's repertoire, then split up again, so as to not compete with each other by working the same territory. The invention of written musical notation was a huge leap forward, in that it enabled the profession of composer/lyricist to be separated from that of the musical performer. Millennia ago, great works were lost completely, because they were not copied enough to survive the deaths of everyone who knew how to reproduce them. That is not a thing that happens when copies are cheap. Even things that were written down have been lost, because copying written materials was not cheap enough until the printing press. If making a copy takes a specialist four hours, and consumes paper and ink, that is nowhere near "close enough to zero". Now, you can copy music in a millisecond, using a device that nearly everyone carries in their pocket, to anyone in the world who likewise carries a similar device. The cost is still not zero. It is just now too small to think about, unless you are making millions of copies per second.