These are the chords given by my program HARMONY, from the abc file above

X:1
T:STEP IT OUT, NANCY
Q:140
M:4/4
L:1/4
K:GMaj clef=treble
|:z z "G"G/2G/2 A|"Em"B e "Em"e e|"G"d B "G"B/2B/2 B|"Em"B e "Em"e d|*
"Bm"B2 "G"G/2G/2 A|"Em"B e "Em"e e|"G"d B "G"B B|"G"B B/2B/2 "D"A F|*
"Em"E2 z z|

Just the chords:
G|Em Em|G G|Em Em|Bm G|Em Em|G G|G D| Em|