Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/8
M:3/4
K:G
['d2 gfgabg af d2 d2 g2 a2', "B2 e^defga b2 b2 c'2", 'd2 gdBdgd gdBdgb agfedf']  
X:1
L:1/8
M:3/4
K:G
 d2 | gfgabg | af d2 d2 | g2 a2 b2 | a4 d2 | gfgabg | af d2 d2 | g2 a2 b2 | g4 :: B2 | e^defga | 
 b2 b2 c'2 | bc'bagf | ag e2 B2 | e^defga | b2 b2 c'2 | bc'bagf | e4 :: d2 | gdBdgd | gdBdgb | 
 agfedf | gfgb d2 | gdBdgd | gdBdgb | agfedf | g4 :|  