{{explanation}}
Note: -	"Change under" means that the Lady holds partners right/left hand in her left/right hand & dances under their raised arms

1-8
: 1s set, "change under" to circle 4H all the way round to left with 2s
9-16
: 1s+2s+3s dance a special Progressive Chain - 1s+2s start by "changing
  under" on sides then "changing under" on sides with 3s **while** 2s
  "change under" across etc. 4 changes to end (3) 1 (2) 4
17-18
: 3s & 4s (end couples) dance in to face up/down dance **while** 1s+2s
  cross (1L+2M dancing under arch made by 1M+2L)
19-20
: 1s & 2s "change under" on sides **while** 3s+4s change places up/down
  dance (4s dancing under arch made by 3s)
21-22
: 3s & 4s "change under" to other sides **while** 1s+2s cross (1M+2L
  dancing under arch made by 1L+2M)
23-24
: 1s & 2s "change under" on sides **while** 3s+4s change places up/down
  dance (3s dancing under arch made by 4s)
25-26
: 3s & 4s "change under" to other sides **while** 1s & 2s advance towards
  partners
27-28
: 1s+2s dance RH across 1/2 way **while** 3s & 4s set facing up/down
29-32
: All dance the following simultaneously:

: (a) 1s dance down under arch made by 4s & "change under" to own sides

: (b) 4s dance to 3rd place & set

: (c) 2s dance up under arch made by 3s & "change under" to own sides

: (d) 3s dance to 2nd place & set