I'm sure it has been said a thousand times already, but most keyboard
'dances' (and particularly by the Bachs) are not literally dances,
rather pieces containing some element of dance rhythm... the
relationship between real dance rhythms and their use in keyboard
music is somewhat complicated.
I wonder if people ever danced to Byrd's Pavans and Galliards.
I do vaguely remember some very old recordings of things like Brahms
Hungarian Dances where there really was no tempo you could designate
as such. This aspect sounded to me chaotic and amateurish, although
the fact that recordings were made indicated that the performers were
probably not so by contemporary standards. So it is entirely possible
that some of the rhythmic habits of the late 19th century were quite
alien to modern expectations. Even today the 'Hungarian Dances' can be
infamous examples of pulling the beat and the tempo every which way.