And don't miss the part about the IRENE system, at the bottom of your wikipedia page: http://irene.lbl.gov http://irene.lbl.gov It uses microphotography of th

And don't miss the part about the IRENE system, at the bottom of your wikipedia page: http://irene.lbl.gov http://irene.lbl.gov It uses microphotography of the disk surface, somewhat similar to that in the OP. They have recordings as early as 1860!