Recording Method: Zoom H4; audacity to cut the trailing noise
Info: One take, no edits
Having no french, or very little, I always thought 'La plus que lente' meant "as slow as possible" but apparently that is not correct. In France at that time there was a distinction between the fast, Viennese waltz and the slow waltz. So this title is actually something like "the most slow-waltz of slow-waltzes" - so it is an stylistic description, not a tempo marking.
It is not, however, as the title might imply, a parody either. Some people, I have noticed, take that tack. If you want to hear how it should be played here is Samson Francoise bringing out its soulful side.
https://youtu.be/1Jqxn5h7FnE