Develop harmonious melodies based on the provided chord structures.
'D', 'Em', 'A7', 'D', 'A7', 'D', 'Em', 'A7', 'D', 'G', 'A7', 'D', 'D', 'A7', 'D', 'G', 'A7', 'D'  
X:1
L:1/16
M:2/4
K:D
 fg |"D" a2aa a2a2 | bab(e g)ff2 |"Em" e2ef gfe2 | B2>B2 BABB |"A7" (Bg2)(B g2>)(g2 | 
 a)age f(fe2) |"D" (df2)e f2(Ad) |"A7" A2>(B2 A2)fg |"D" a2 a4 a2 | babe gff2 |"Em" e2f2 gfe2 | 
 B2>A2 B2(A2 |"A7" A)(AB)A d(Bd)e |"D" fef(f a2)(B2 |"G" g)ege"A7" f2(Ae) |"D" (df2)(d f2) |: (DE | 
"D" F)FB(B A2)(A2 | B)AB(B | A2)(DE | F)FBB A(DF2) |"A7" E2>(D2 E2)DE |"D" FFBA B2>A2 | 
 BAB(B d2)ef |"G" gfgf"A7" e(Ac2) |"D" (df2)(d f2) :|  