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 E2']  
X:1
L:1/8
M:4/4
K:G
 (D3/2 E/) | (G3/2 F/)(GA) B2 (AG) | (A3/2 G/)(AB) d3 e | (d/ B3/2) (A3/2 G/)(Ac)(BA) | 
 G2 E2 E2 (DE) | G3/2 (F/)(G)A B2 AG | A3/2 G/AB d3 e | d/ B3/2AGAcBA | G2 E2 E2 ef | 
 g3/2 f/ g3/2 a/ g2 fg | agab a2 ge | g3 abag e | g2 d2 d2 g3/2 e/ | dBAG A2 Ae | dBAG E2 ge | 
 dBAGAcBA | G2 E2 E2 ||  