Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:9/8
K:G
['GED GAB', 'edB BAB']  
X:1
L:1/8
M:9/8
K:G
 AGE A2 B G2 B | A2 E ABd e2 f | gdB BAB GBA |1 GED GAB dcB :|2 GED GAB d3 || efg edB BAB | 
 gbg edB d3 | efg edB BAB | GED GAB d3 | efg edB BAB | g2 g edB d2 g | e2 g edB BAB | 
 GED GAB dcB ||  