Both Maple shade and some Kimber are silver plated over copper. I don't know if that extra property could make the copper sound different. A lot of high end cables are either silver plated or have a varied degrees if silver core.

http://www.hifichoice.co.uk/review_read.asp?ID=1587

http://www.innerear.on.ca/accessories/nordost.html

http://www.hifichoice.co.uk/review_read.asp?ID=417

http://www.hifichoice.co.uk/review_read.asp?ID=419

http://www.soundstage.com/revequip/silversmith_silver_cables.htm

http://www.hometheatersound.com/equipment/nordost_cablesystem.htm

Yes copper is copper but these ones have a silver lining.
I would definitely like to see if a someone can blind test a silver wire vs a ratshack 16g lampcord with an upper end revealing speaker. What we are looking for is not which is better sounding but if there is a difference at all in sound charateristic.

Saturn

http://www.quadloft.com/hometheater- new HT