I heard tell since vinyl records are actual grooved recordings that some people (especially on the really old ones) can read the grooves and tell what the music is.
Is this true or an urban legend?
It’s a trick. Anyone can do it but only if each record is in a different broad category. You can tell by the spacing between the different tracks (tracks, not the groove) if it’s contemporaty music or classical. If it’s classical, you can tell how many movements there are to see what it is.
Haj
On a related note:
Arthur G. Lintgen was (semi-) famously able to do this, thanks to a good eye and an encyclopedic knowledge fo classical music. I can’t find much of a cite beyond this one at the Skeptic’s Dictionary. Scroll to bottom of page; the final section in reddish-brown begins the brief discussion:
http://skepdic.com/psychdet.html
I must admit that I have no idea how reliable the Skeptic’s Dictionary is, but they seem to have cites for most of their info.
If you spend enough time staring at records, you can learn to pick out loud and soft passages, songs with a strong beat etc. High amplitude sounds produces deeper cuts in the grooves than do low amplitude sounds. Deeper grooves reflect less light than shallow ones. The rhythm also shows up as periodic changes in amplitude, hence reflectivity. I doubt that many people ever got good enough to name a tune solely from it’s appearance on vinyl, but there is information to be had from looking at the grooves.