I tried this decades back with a (then) expensive Hughes HeNe laser, a 20x microscope eyepiece for beam focusing and a phototransistor detector feeding a HeathKit audio amp.
The laser spot size covered about three grooves. But for playing three grooves at once, it sounded good enough to be interesting. Didn't follow up, however.
The laser spot size covered about three grooves. But for playing three grooves at once, it sounded good enough to be interesting. Didn't follow up, however.