Create a series of chord progressions to improve the harmonic structure of the given music piece.
|: D2 A2- | AG AG/F/ | E>F GA | F2 E2 | D2 A2- | AG AG/F/ | E>F GA | 
 F2 E2 :: DF EF/E/ | DF EF | G>F ED | F2 E2 | 
 DF EF/E/ | DF EF | G>F ED | FE D2 :|  
X:1
L:1/8
M:2/4
K:Dmin
|:"Dm" D2 A2- | AG AG/F/ |"A7" E>F GA |"Dm" F2"A7" E2 |"Dm" D2 A2- | AG AG/F/ |"A7" E>F GA | 
"Dm" F2"A7" E2 ::"Dm" DF"A7" EF/E/ |"Dm" DF"A7" EF |"Gm" G>F ED |"Dm" F2"A7" E2 | 
"Dm" DF"A7" EF/E/ |"Dm" DF"A7" EF |"Gm" G>F ED |"Dm" F"A"E"Dm" D2 :|  