Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:4/4
K:Ador
['A2 BG A2 Bd', 'a2 ea a2']  
X:1
L:1/8
M:4/4
K:Ador
 A2 BG A2 Bd | egfa gedB | G2 BE GEBE | G2 BA GEDG | A2 BG A2 Bd | egfg efga | gfge d2 ef |1 
 gfgd BAAG :|2 gfgd BA A2 || a2 ea a2 ea | a2 ba gede | g2 ba gbag | gbaf gedg | a2 ea a2 ea | 
 a2 ba gede | gfge d2 ef |1 gfgd BA A2 :|2 gfgd BAAG ||  