Are Cds made of dysprosium?

Question

As dysprosium has alloys with useful magnetic properties I would think it is more likely to used in the CD player than the CD, but I'm quite willing to be corrected.

I doubt it. I would think it was too expensive for CD disks. The first reference below does NOT list the use of Dy in the manufacture of CD disks, but the other two list CD disks as a use for Dy. My best guess is that both of the latter came from the same source and there is no documentation here. You can get all kinds of information on the web. Some is good and some not so good. Personally, I still doubt it but that's just a peronal opinion. http://www.osta.org/technology/cdqa15.htm
But www.webelements lists that as one of its uses.
http://www.webelements.com/webelements/elements/text/Dy/uses.html

http://www.chemicool.com/elements/dysprosium.html