Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:4/4
K:D
['A>Bd>e f>ed>A', 'a>fd>e f>ed>A']  
X:1
L:1/8
M:4/4
K:D
 A>Bd>e f>ed>A | (B<e) e>f g>f e2 | A>Bd>e f>ed>A | (B<d) A>G (F<D) D2 :: a>fd>e f>ed>A | 
 (B<e) e>f g>f e2 | a>fd>e f>ed>A | (A<d) A>G (F<D) D2 :|  