EU - General Ideas

i have thought up a good idea for part of the song which involves quite a complex method. we use a program to slow down the song to exactly 50% of its real speed and then i learn it. we then go to quite a busy location like trafalger square and i mime it at the half speed. then when it comes to editing we can speed it up to 200% and it will look as though i am the only one moving at normal speed and everyone else will be rushing.