Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:6/8
K:D
['DFA dAF']  
X:1
L:1/8
M:6/8
K:D
|:"D" F3 FED | FAF"A" EFE |"D" DFA dAF |"A" EDE GFE |"D" F3 FED | FAF"A" EFE |"D" DFA dAF |1 
"A" EFE"D" D3 :|2"A" EFE"D" D2 g |:"D" fed edc |"^(G)" dcB"^(A)" AFA |"D" fed"A" edc | 
"G" dfb"A" a2 g |"D" fed"A" edc |"D" dcB AFE | DFA dAF |1"A" EFE"D" D2 g :|2"A" EFE"D" D3 :|  