The original wax drums were cut vertically “hill-and-dale” and we owe the credit to Thomas Edison.
Then came Berliner and his flat disc that adopted the lateral movement, why not?
And then later came the Acetate Bakelite, Vinyl for the Radio Broadcast Transcriptions that offered greater silence . Yes but the idler wheel drive turntables showed high levels of rumble. Rumble was only picked up with lateral movements so the industry reverted to “vertical”…..
The very reason western electric 9a and associated equaliser has the switch for vertical or lateral or likewise on the RCA transcription tables and equalisers was to set according to recorded method, both existed….and still do!
Okay all the above is mono….
Then came the event of stereo….with ups and downs and all arounds….more on this in later article…
So for now and if you are into vintage records check if they are vertical of lateral….and yes use the correct needle…