Binaural

This is another one I haven't seen before.

  

This nicely pigmented album only appears to have two tracks but in reality it only has one since it is a binaural recording which requires two cartridges to play it.  This means you need a tonearm with two headshells,

The arm appears to work like a linear tracker and may have been the inspiration for the Garrard zero 100.  Here is a crude video showing it in action and some liner notes.