[Reverse] Change-O

Change-O, from columns (typically normal ones): #1 and #2 Circulate, #3 and #4 Cross Over Circulate.

Reverse Change-O, from columns (typically magic ones): #1 and #4 Circulate, #2 and #3 Cross Over Circulate.

Perhaps a useful way to remember this and make sense of it is as follows: Think of a magic column as one in which the ends are "correct" and the centers are "wrong". (Some people actually think this is true. Good challenge dancers know better. It is just an artifice for these calls.) Then Change-O means "Circulate while going into magic". That is, cross over if you will finish in the middle. Reverse Change-O means "Circulate while coming out of magic". Cross over if you started in the middle. Of course, if you can figure out what to do in time to do it in one smooth motion rather than two separate actions, so much the better.