This was a neat article. As a side note, here is a list of curiosities in optical: https://en.wikipedia.org/wiki/List_of_albums_with_tracks_hidden_in_the_preg

This was a neat article. As a side note, here is a list of curiosities in optical: https://en.wikipedia.org/wiki/List_of_albums_with_tracks_hidden_in_the_pregap https://en.wikipedia.org/wiki/List_of_albums_with_tracks_hid...