I saw an explanation for why it is out of tune. Higher notes should have close grooves, and lower notes should have further grooves. When they calculated the distance apart for the grooves for each note, the distance they calculated was the wavelength, so the grooves should have been cut at a distance measured from the center of each groove… Instead they cut the grooves measuring from the end of a groove to the start of the next groove… pitch shifting each note lower by the same constant.