Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:4/4
K:G
['G2 BG dGBG', 'gdBd edBd']  
X:1
L:1/8
M:4/4
K:G
 G2 BG dGBG | FADA FADA | G2 BG dGBG | egfa gedB | G2 BG dGBG | FADA FADA | G2 BG dGBG | 
 egfa g2 (3edB |] gdBd edBd | gabg agef | gdBd edBd | egaf g3 f | gabg efge | dedc BGBd | 
 e2 eg edBd | egfa gedB |]  