The first thing that came to my mind was the music in one of the PT storylines...it was supposed to be set the 19th century but the piano composition sounded more like something from a movie score from the 1940's. Sorry for the lack of detail but, I couldn't recall the exact storyline.
You're probably thinking of "Joanna's Theme" which is actually from the Normal Time 1840 storyline, CastleBee. Although it is a beautiful piece, it certainly was historically out-of-place. It was eventually used as the theme music for the movie "Night of Dark Shadows," a very film noir type of melody.
My gripe with the 1840 plot was Gabriel's wheelchair. Although it had an old-fashioned-looking wicker back, the rest of it was modern, with rubber wheels and glistening aluminum hand grips. Obviously, the props man took a regular wheelchair and replaced the seat, leaving the rest of the contraption. Either that, or Blanche Hudson's wheelchair somehow tumbled down the time-travel staircase and old Ben Stokes found it, figuring with a few mid-nineteenth-century replacement parts, it would work for sad, handicapped Gabriel.
Gerard
