Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/8
Q:1/4=120
M:6/8
K:G
['D GAG GAB ded dBG BAB AFD', 'def g2 e']  
X:1
L:1/8
Q:1/4=120
M:6/8
K:G
 D | GAG GAB | ded dBG | BAB AFD | EFE E2 D | GAG GAB | ded dBG | BAB AFD | E3 G2 :: e | def g2 e | 
 fed edB | def g2 e | afd e2 f | def g2 e | f2 d efg | dBG GAB | ded dBG | BGB AFD | EFE E2 D | 
 GAG GAB | ded dBG | BAB AFD | E3 G2 :|  