Oxygen free copper is nice to reduce corrosion, but never mind OFC or OCCC failing in blind tests, or silver
Silver is a mind-blower for me. Because silver creates its own set of problems in terms of signal conductivity. Sometimes I wonder if there's just an opulence aspect going on there. Like, if a manufacturer thought they could make it cost-effective (for them, not for you), they'd put out a 14k gold wire, just to see if it'd sell.
In fact, I seem to recall back in the 80's reading a Stereo Review article about gold speaker wire. But I couldn't say for sure who did it or what purity level it was.

