Agree with Ed. Did a quick search on the internet and turned this up:
CuO (copper oxide) has a magnetic susceptibility of +267 while AgO (silver oxide) has a magnetic susceptibility of -19.
By way of comparison, the magnetic susceptibility of FeO (ferric oxide, (rust) is 293.
The much higher magnetic susceptibility of CuO means the skin depth will be *very* thin, and net skin resistivity very high. Meanwhile, the negative value for AgO means that the skin depth will be greater than anticipated.
As with steel versus copper we have to look beyond DC resistance to find out which material is better suited. It turns out that oxidized copper is almost as bad as oxidized steel That is why silver plating is often suggested for conductors.
Although the conductivity of silver is only 6% better than copper, when each surface is compared in an oxidized state, silver is a far superior conductor than copper.
Short answer, if you like the sound of copper, keep it free of oxidation. My own suggestion to polish and renew either material is Flitz polish from Germany. The best Flitz is called Polier and second best is Flitz metal polish.