Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
M:3/4
K:D
['b>a f2 d2', '^d>e c>A e>c d>A f>d a>f g>e']  
X:1
L:1/8
M:3/4
K:D
|: b>a f2 d2 | b>a f2 d2 | f>a g>e c>e | A>c d>f A2 | b>a f2 d2 | b>a f2 d2 | f>a g>e c>e | 
 A>c d2 D2 :: c>d ^d>e c>A | e>c d>A f>d | a>f g>e c>A | e>g f>a ^g>a | f>d ^d>e c>A | 
 e>c d>A f>d | a>f g>e c>A | B>c d2 D2 :|  