a couple of links to share is all.
first is a collection of stunning images done by the institute of optics at the university of rochestser. they put a vinyl record under an electron microscope to see what those grooves look like REAL close.
check it out:
See more via Synthgear
second is a pretty cool ad for technics cassettes from japan, circa the mid-80s. hat tip to Yoga Records for this one.