What was the point of CD-augmented tabletop RPGs?

While reading an old article in White Wolf Magazine I learned about cd-augmented tabletop RPGs. Issue #43 had a brief describing what seems to be the first example, First Quest:

First Quest features a 50-track audio CD that guides you through four adventures …

What was the purpose of this CD? What was the content and what did it add to the gameplay experience that a more traditional book-and-mortar approach didn’t offer?

The wikipedia article on First Quest mentions the CD, but doesn’t say what is really on it. Apparently the CD helped guide players through a couple of adventures, but I’m not sure what that means.

Though I’m using First Quest as an example, the White Wolf brief also mentioned that TSR was planning on releasing similar products for the Mystara campaign setting. Ideally I’d like to know broadly what CD-augmented games added over other existing RPG products in terms of functionality, game play experience, or something else.