Produce music using the specified musical structure depicted in letters along with the provided musical theme.
X:1
L:1/8
M:12/8
K:D
['G FEF D2', 'g f2 e']  
X:1
L:1/8
M:12/8
K:D
|: G | FEF D2 d c2 B A2 G | FEF D2 F E3 E2 G | FEF D2 d c2 B A2 G | F2 D E2 C D3 D2 :: g | 
 f2 e d2 A Bcd A2 g | f2 e def e3 e2 g | f2 e d2 A Bcd A2 G | F2 D E2 C D3 D2 :|  