Silver plated copper

The primary original reason to silver plate copper wire was corrosion resistance. Military, particularly aviation like silver plated copper..Plenty of Mil Spec Silver plated Teflon insulation wire for sale on eBay.                           
I have purchased plenty of it.
No special reason in audio use, particularly up against long grain OFC single crystal 99.999 etc copper.        
Silver plated copper is better for digital, computer and video in general.

Now you've got me curious Elizabeth.Silver and copper both oxidize quickly so I wanted to understand how the silver could actually protect the copper....Anyway I found some info about it in case anyone is interestedhttps://www.finishing.com/461/41.shtml

That link was about as clear as mud. No offense to you personally.

Some of the most expensive cables made, such as Jorma and MIT use copper exclusively.  IMO, some cable makers may use silver-plated wires only to be able to use the word "silver" in their marketing.  I don't think we, as consumers, have the opportunity to compare the exact same cables with copper v. silver-plated wire, so it's probably impossible to tell for sure.  But I'm open to the concept that silver-plated wire may sound different than pure copper.  

Silver is the "best" electrical conductor of electricity, marginally better than copper regarding conductivity. Silver will oxidize just as copper will, but silver will not corrode like copper. Unless I could have silver wire throughout my system (including internal wiring of components and speakers) I would not bother with just interconnects or speaker cable in silver.