I've always been a fan of Mike Oldfield. In 1994, Mike released his 16th album, The Songs of Distant Earth, based on and inspired by Arthur C. Clarke's SF novel of the same title (and with Clarke's full approval and cooperation). The CD was re-released very shortly afterward as an "enhanced" CD containing CDROM content including a VR experience built upon the Myst engine. A second edition of the enhanced CD added more multimedia content including the full-length video for the second track, "Let There Be Light".
So far, so good. But all is not perfect in the digital world. There are two problems with the enhanced CD.
The first is that the CDROM data content is encoded and formatted for PowerPC Macs running OS7 through OS9 — because, in 1996, the Mac was arguably the best common graphics platform around. If you try to load the enhanced CD into a Windows or Linux PC, it can't read that track. Current versions of OSX no longer include OS9 compatability and cannot run PowerPC binaries, so a current OSX Mac can't read it either.
So, forget the multimedia content, unless you have a classic Power Mac around that's still running either OS9 or an older version of OSX with the OS9 compatibility installed (which is really just an embedded OS9 installation). But you can still play the music, right?
Well ... maybe. You see, the other problem is that the CDROM track is the first track on the CD. And if your optical drive and your computer can't read that first track, they can't play the CD — and in fact, in the case of Linux and Windows at least, they fail to even detect valid media in the drive. If you're using an ordinary "dumb" standalone CD player, it will simply skip the first track (because it can't read it either) and play the rest of the CD. But if you're trying to play it on a computer? You're pretty much boned. (You might be able to skip past that first track and play the rest of the CD on an OSX Mac. I haven't tried it. I don't do Macs.)
So, if you bought the enhanced CD and want to play it on a computer, you're pretty much out of luck. And if you're only going to play it on a regular CD player ... well, then you can't access the multimedia content, so why would you get the "enhanced" CD?
So now you want to find a copy of the audio-only original-edition CD? Good luck with that.
Well, hey, it probably seemed like a great idea at the time. But less than fifteen years later, its "enhanced" multimedia content is de facto unplayable, because it was coded for a niche system that de facto doesn't exist any more outside of computer museums and a few relict private collections.
There's a lesson here, and it's one that's already a significant concern among people in the computer industry who think ahead about things like this:
"Will we still be able to read this medium, or this data, in fifty years?"
Here's one we can't read after only fifteen.