Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:6/8
K:D
['FAd f2 a', 'AGE D2', 'afd BGE A,A,A, CEA gec d2 g']  
X:1
L:1/8
M:6/8
K:D
|: FDB AGE | FAd f2 a | ggb ege | Bcc AGE | FGB ABG | FAd f2 a | bge cAF | GFE D2 E :: F2 D DED | 
 FAd fdA | g2 e efd | Bcd ecA | B2 g bge | Adf afd | FAd gec |1 AGE D2 E :|2 AGE D2 B |: ABA fff | 
 ab^g afd | BGE A,A,A, | CEA gec | d2 g eff | ab^g afd | Bge cec |1 AGE D2 B :|2 AGE D3 ||  