Develop harmonious melodies based on the provided chord structures.
'D', 'G', 'D', 'A', 'D', 'G', 'D', 'G', 'D', 'D', 'A', 'D', 'G', 'A', 'G'  
X:1
L:1/8
M:4/4
K:D
 d3/2 |: e/ |"D" f>A A/A/A"G" B<G d>e |"D" f>A A/A/A"A" B<d d>e |"D" f>A A/A/A"G" B<G g2 | 
"D" f<a e>d"G" B<d"^(D)" d3/2 :: e/ |"D" f2 f<d f2 f<a |"D" f2 f<d"A" e>f a2 | 
"D" f>g f>d"G" e>f g>e |"A" a>f e>d"G" B<d"^(D)" d3/2 :|  