Karaoke is a bit of a gray area with gaming preservation. By gaming console, Redump and No-Intro dat any kind of release. MAME seeks to preserve and emulate Karaoke more widely, as I very surface-level-understand.
Karaoke releases in general are usually CD+G format - Redbook audio tracks with "+G" graphics subchannel data that displays images (usually lyrics). VCD and even DVD-Video are common platform agnostic Karaoke formats as well.
Philips CD-i branded Karaoke discs I've crossed paths with thus far are CD-i Ready. Karaoke CD-i releases aren't super will documented, and as a video game archeologist who has tracked down countless rare / unknown releases for many systems - these CD-i Karaoke discs intrigue me.
There are at least a handful of Karaoke discs out of Sweden for example, but little documented as Swedish discs have proven tricky to track down in the past as my fellow redump comrades & I completed the preservation of PlayStation 1 Europe releases.
But the more well known / documented releases came out of the home of Philips, the Netherlands.
With the help of a Dutchie gentleman I was able to track down a good handful of the NL releases.
Among the releases is Karaoke Vol(ume) 1-4. Among them, I've found a couple variants - today I show off this one:
