The Ballroom stance takes quite a while for most people to develop because it requires that one should not slouch at all. In fact, Men should stand perfectly upright & ladies should arch backwards a little to the left so that there is space between the upper bodies, but contact in the pelvic area. This stance should be the same for the Slow Waltz, Viennese Waltz, Foxtrot & Quickstep but not Tango. When jazz music changed to Swing, older & / or richer people tended to dance Quickstep or Foxtrot (depending on the speed of the music, whereas the Lindy hop &/or swing dances tended to be the favoured dance of younger &/or poorer people or when the music speed is somewhere in between the 2.
Some prefer a dance known as Rhythm which can equally be danced to the same music. Nowadays many call this the Social Foxtrot. Unfortunately too many people are now also calling "Rhythm" "Foxtrot" which is misleading as can be seen in the following clip which really shows "RHYTHM" NOT FOXTROT.
When jazz music changed to Swing, older & / or richer people tended to dance Quickstep or Foxtrot (depending on the speed of the music, whereas the Lindy Hop &/or swing dances tended to be the favoured dance of younger &/or poorer people or when the music speed is somewhere in between the 2. Lindy Hop came from the Charleston, so in the clip below we can see both dances as performed on TV in recent years. Note how some Charleston steps are incorporated into the Quickstep.
American Country Western dancers added their own flavour to the music & dressed as cowboys, & so changed the dance to the TWO STEP as shown below. Note that this is not to be confused with the Old Time Two Step.