Compose a melodic line that follows the provided chord sequence.
'D', 'A7', 'D'  
X:1
L:1/8
M:2/4
K:none
[K:D]"D" Ad/d/ dd | FA/A/ AA | DF ED |"A7""_=C" F2 E2 | Gc/c/ cc | EG/G/ GG |"_=C" AG FE | 
"D" D2 D2 :|  