Originally Posted by equinegirl26
Simple Changes: You canter and if you get the wrong lead, you slow down to a trot.
Flying Changes: Switching leads while cantering. :)
Not always :P In dressage tests over elementary level (3rd level in US??), they ask for simple changes of leg, often right down the centre line to test how straight your canter and transitions are, or on a serpentine.
Simple changes are a great lead up to flying changes. It will develop a great half halt and much more response to your seat and leg. It is also generally performed as a canter-walk-canter, not canter-trot-canter, and ridden correctly asks for a high degree of balance and substantial amount of strength of the hind quarters to enable to horse to sit in the downward and push up back into canter.
When the horse strikes off onto the wrong lead, pulling them back into trot and asking again generally involves a lot of unbalanced activity and most of the time you see the horse on the forehand. NOT a simple change ;)