Produce a musical expression that follows the indicated alphabetical structure while integrating the provided thematic material.
X:1
L:1/8
M:6/8
K:D
['DFA =c2 A def gag fed', 'dfa dfa']  
X:1
L:1/8
M:6/8
K:D
 D | DFA =c2 A | def gag | fed cBA | GFG AFD | DFA =c2 A | def gag | fed dcB | Add d2 :: A | 
 dfa dfa | dfa agf | ceg ceg | ceg gfe | fef gfg | aga bag | fed dcB | Add d2 :|  