system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does the needle of a record player ‘read’ the music on a vinyl?
gpt
It vibrates.  The needle is held at the base, while the tip is allowed to ride in the groove of the record.  That groove causes the needle to vibrate (up and down, not side to side), and that vibration is picked up by whatever amplification method is used by that particular record player.  In mechanical players, that amplifier was a big horn that acoustically amplified the sounds, while today the stylus (what we call a needle) is held by a cartridge that either has a piezoelectric element or actually has a small coil and magnet setup to turn the vibrations into electrical energy, which can then be amplified.