- May 30, 2022
Glad this is already well-known, as it makes it much easier to move forward. I had posited mistracking as the cause but it was only conjecture. Seems that others had the same idea decades ago
This photo from comment #34 (shown below) is quite problematic for establishing that your own photographed anomalies are a result of mistracking. What I see in the above referenced photo is continuous fletches of anomalous light along the entire distance of the groove segment. Whereas in your own photos (an example shown underneath) only see sporadic fletches of anomalous light separated by clear intervals of the groove segment without anomalous light.
They are not identical markings, although share some similarities, thus definitively ascribing mistracking as the cause of your cases seems premature. I think it is logical to suppose that a song on your photographed records' side(s) were most commonly played in their entirety so that the song's grooves endured the same tracking throughout. Yet your anomolies in a song's grooves show up sporadically instead of consistently.