Scarcity is a limit in resources. The music labels are using the government to limit their songs by stopping you from creating copies. Without these restrictio

Scarcity is a limit in resources. The music labels are using the government to limit their songs by stopping you from creating copies. Without these restrictions you would be able to make an effective unbounded number of copies because each copy has a resource cost of basically zero--there would be no scarcity. With these restrictions, you can only make as many copies as the labels allow you to, which means the number of copies is bounded. I should note that this is orthogonal to whether you think they are justified in seeking to be paid for their songs: in either case, they ensure being paid by making the songs more scarce using copyright.