This is simplified and might be a tad wrong (it's been a little bit), but:
All sound you hear is waves transferred by vibrating air molecules. Your ear receives these waves from the air and converts them into electrical signals that go to your auditory cortex.
These sound waves will differ in shape depending on different qualities of the sound, like pitch or loudness.
The groove on a record is cut by vibrating a lathe according to the wave you want to be reproduced. When you play it back on a turntable, the needle will vibrate based on how the groove is cut and will reproduce the wave as the needle passes through. By amplifying the needle as it vibrates, you can put it through speakers, which also vibrate to push air molecules around for your ears to pick up. That's how you get Led Zeppelin! Or whatever else you're listening to! This whole thing is still bonkers!
I have just the 1941 Argentinian philosophical short story for you.
