Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
Q:1/4=190
M:6/8
K:D
['d2 e fdB', 'B3 BAF ABc dcB', 'ede fdB']  
X:1
L:1/8
Q:1/4=190
M:6/8
K:D
 A | d2 e fdB | d2 e fdB | AFE EFE | AFE EFA | d2 e fdB | d2 e fdB | AFD DED | AFD D2 :| A | 
 B3 BAF | ABc dcB | AFE EFE | AFE EFA | B3 BAF | ABc dcB | AFD DED | AFD D2 :| f | g3 f3 | 
 ede fdB | AFE EFE | AFE EFA | gbg faf | ede fdB | AFD DED | AFD D2 :|  