What's actually kind of funny is that old laserdiscs were analog. And contained analog video as well as analog and digital audio sound tracks.
In hind sight maybe that was the future.
As I understand it, the pits and lands on a disc don't need to be constant size as the are on a digital CD (in this case used to the define ones and zeros). An analog signal can actually be encoded on the disc using variable sized pits and lands arranged in linear sequence. A laser can then pick then pickup that analog signal with no D/A conversion required. Pretty much like a turntable, but without the needle and associated wear, dust, static, etc. issues.
EDIT: a little further research on Wikipedia turned up this.
"An earlier analog optical disc recorded in 1935 for Licht-Tone Orgel (sampling organ)"