The essential difference between the emergence of Jive and its american counterparts was the music.. in the late 40s/early 50s there was a paradigm shift from 2/4 to 4/4, and the speed of the music speed increased, from the more sedate speeds of E and W coast swings . The powers that be in the UK ( at that time ) were responsible for adapting the substantial changes .. the reason ?.. the Bop/Jive being done by the American forces, to them, looked out of control, and too wild for the general publics acceptance in the Ballroom world of the time.. My coaches ( as all I guess did ) were against it, if one was in the ballroom div (I still danced it on a regular basis ! ). ... many public ballrooms in the UK banned it !! ( some roped a section of the floor for "boppers " ) It ( the time sign. change ) also affected Quickstep..