Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
Q:1/4=100
M:2/4
K:G
['gdBG gdBG', 'df ecdB c/B/A/G/', 'gefd ecdB c/B/A/G/']  
X:1
L:1/8
Q:1/4=100
M:2/4
K:G
 (e/f/) | gdBG | gdBG | (c/B/A/G/) FA | fAA(e/f/) | gdBG | gdBG | c/B/A/G/ F/G/A/c/ | BG G :: B | 
 (G/A/B/c/) df | ecdB | c/B/A/G/ FA | fAAB | G/A/B/c/ df | ecdB | c/B/A/G/ F/G/A/c/ | BG G :: 
 e/f/ | gefd | ecdB | c/B/A/G/ FA | fAA(e/f/) | gefd | ecdB | c/B/A/G/ F/G/A/c/ | BG G :|  