Not sure that the bit about tempo is always true. If you go to a club the mix might include
Playford - sometimes old and stately (though there is 'zesty Playford' too)
dances that crossed the Atlantic then returned transformed, danced as a smooth walk to fast music
dances that might be called 'barn dances' or 'ceilidh dances', sometimes danced to slow music to allow dancers to get further off the ground, sometimes to faster music and a flatter step (depending on the age-range of dancers)