Yeah! It's dope. With this new understanding I'll circle back around. In an indirect sense the groove of a record represents how far our eardrum should be from its "silent resting position" over time. That's it. The brain is what takes that complicated signal that varies over time and makes something it recognizes out of it.

And then the information encoded on a CD, or magnetic tape, or in a compressed audio file is just the same thing: distance of eardrum from neutral over time.

Oh, and stereo and surround sound and all that is just different audio tracks that play out of different speakers at a synchronized time. Again, it's our brain that notices it hears a flute in the left ear very slightly before it hears it in the right ear and thus feels like that means there's a flute to our left. But there's nothing "flute left" about either individual signal, they're just different audio that we detected a slight difference in from ear to ear.