Construct a melodically pleasant tune that corresponds with the specified chord structure.
'D', 'G', 'D', 'Bm', 'D', 'G', 'D', 'Em', 'Bm', 'Bm', 'D', 'G', 'D', 'G', 'D', 'D', 'G', 'D', 'Em', 'Bm', 'Bm'  
X:1
L:1/8
Q:1/8=300
M:6/8
K:D
 AG |"D" FAA dAA |"G" BAB"D" dAG | FAA dfe |"Bm" dBB BAG |"D" FAA dAA |"G" BAB"D" def | 
"Em" gfe dfe |1"Bm" dBB B2 A :|2"Bm" dBB g2 :|"D" faa"G" gbb |"D" afe dcd | faa"G" gbb | 
"D" afd e2 g |"D" faa"G" gbb |"D" afe def |"Em" gfg efe |1"Bm" dBB B2 g :|2"Bm" dBB B2 B :|  