{{explanation}}
2 chords - 2nd chord 3s & 4s cross to opp side

1-4
: 1s+2s also 3s+4s dance 1/2 reel of 4 across (1L+2M & 3M+4L pass RSh, 1M
  & 4M dance across & cast down/up to join end of 1/2 reel), 1s & 4s 1/2
  turn partner LH following into …
5-8
: 1s+4s dance 1/2 LH across, 4s+1s turn LH on sides. (2) 4 (1) 3
9-16
: 2s+4s+1s+3s dance RSh reels of 4 on sides
17-24
: 4s+1s join RH in centre, LH with 2s/3s & dance 1/2 RH across, 1s & 4s
  face corners; all set, all 1/2 turn corner RH to end 2L followed by 2M
  & 3L followed by 3M in tandem facing corners (on 1st corner diagonal)
25-32
: 3s+2s dance alternating tandem reels of 3 on sides (3s pass 1M RSh, 2s
  pass 4M RSh to start), 2s & 3s end in middle, 2s towards Ladies' side
  facing down, 3s towards Men's side facing up, still in tandem
33-36
: 2s & 3s dance up/down to 1st/4th place, separate, (1s & 4s step down/up
  35-36), 2s+3s turn partner 2H. 3 1 (4) (2)
37-40
: All circle 8H 1/2 round to left. End 3 1 (4) (2)