In the context, it's clear. CDs are tangible.
Not even that: CDs are read-only, non-volatile and the data is uncompressed and unencrypted. Those are all pretty desirable features when paying $evilco for some music, even if you're just going to rip it and stick it in a box as a backup. That you get cover artwork is a fringe benefit, cancelled out by the low storage density.
But the way people listen to music changed. You don't really have a record collection any more, you just summon up a track from the cloud as the whim dictates. Be it through iTunes, Spotify or Youtube.
Remember when software came with real paper manuals, and the first thing it told you to do was to make a working copy of the disks? It's going the way of that...
Also: Brothers in Arms is 30? Now I feel old...