Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
M:6/8
K:D
['dcd fed dcB A3 Bgg', 'dcd BGG e2 d cAA g2 f']  
X:1
L:1/8
M:6/8
K:D
|: A | dcd fed | dcB A3 | Bgg Aff | efd cee | dcd fed | dcB A3 | Bgg aff | edc d2 :: f | f<ad dcd | 
 BGG e2 d | cAA g2 f | efd cee |1 a2 d dcd | BGG e2 d | cAA g2 f | edc d2 :|2 dff egg | dff ecA | 
 f3 gec | Adc d2 ||  