You assume that without copyright no new music will be created. But I observe that lots and lots of music predates the era of copyright (copyright was extended to cover music, too less then 100 years ago, music existed for centuries without copyright!).
We can just look on how it was done before, it's not big deal.
Some other creations were never created in era before copyright (movies and programs, for example), but it's not entirely clear if they need copyright or they only need the technology.
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