Hi there,
I played this game in primary school in the mid 80's in Auckland, New Zealand. It progressed from ankles, to knees, and then hips. Once those levels had been completed, we used only one one leg for ankles and knees, and turned sideways to make the elastics thinner for the hips level. Each level had a different chant. There was also a level called carrots, where one person had two legs supporting the wide end of the elastics, and one person had one leg supporting the thin end of the elastics causing a triangular, or carrot, shape. The only chant I remember is the "jingle jangle" one, which we used for the ankles level. There were three or four different jumping sequences that we played with, one involving crossing the elastics over, then jumping to release them, and one involving jumping onto the elastics. The jingle jangle chant was used for the simplest sequence which involved jumping within, without, and straddling the elastics.
I'm in Japan now and was reminded of the game when I heard about "gomutobi", literally "rubber-flying/jumping". A woman I work with told me it was very popular when she was in primary school during the 50's, when they used to loop rubber bands together, and that it originated sometime during the war.
Perhaps if enough people submit their memory of the game to this thread, I will eventually remember the entire game accurately, as I played it all those years ago!