A CD is not any more of a hard copy than your harddrive is. CDs are digitally encoded just like harddrives, they use pretty much the same method of storing data.
Technicalities aside, they are entirely obsolete. If you want the experience of inserting a physical volume of data into a player, get an MP3 player with SD card support and put your music on an SD card. You can store 128gb+ on an SD card which is like 1/20th of the size of a CD that can only store 870mb of data on it. CDs are the definition of obsolete.