#optical disc

DualDiscs! Do you remember them?

The idea was that they were double-sided discs, with one being a regular CD audio album and the other being DVD. The DVD side would usually have the full album at a higher sample rate, and often included bonus video material like making of documentaries and music videos.

These felt like a very cool idea and were a definite step up over Enhanced CD in terms of the quality of the bonus content, as even a single layer DVD was more than enough for a few standard definition music videos. Of course, they were also easier to damage and had compatibility problems with some players - though the music industry probably didn't mind that they were harder to rip.