Beats 1-2: dancers #1 and #4 hop backwards while dancers #2 and #3 hook approximately 3/4 of the way around each other (approximately 270º), passing right shoulders. At this point, the dancers are in a straight line, at a 45º angle to the music.
Beats 3-12: dancers pass each other, alternating shoulders. The first pass is by the left shoulder (because #2 and #3 already passed by the right), then right, then left, etc. When you get to the end of the line, loop around your left shoulder instead of passing someone. (Remember that everyone else is passing, so you have to “skip” a shoulder as you do this.)
Beats 13-16: Dancers #1 and #4 loop around slowly to their original places. Dancers #2 and #3 meet and once again go 3/4 of the way around each other (approximately 270º) to end up in their original places.