Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
M:6/8
K:D
['', 'fdB AFA BdB', 'a3 baf afd Adf edB']  
X:1
L:1/8
M:6/8
K:D
 A, |: DFA BGF | E2 e fdB | AFA BdB | AFD EDA, | DFA BGF | Ege fdB | AFA BdB | AFE D3 :| d2 f a3 | 
 baf afd | Adf edB | Aaf edB | Adf a3 | baf afd | Adf edB | AFE D3 :|  