Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:6/8
K:C
['A/B/ c2 c cde dBG GAB cBA', 'g>ag gfe dBG']  
X:1
L:1/8
M:6/8
K:C
 A/B/ | c2 c cde | dBG GAB | cBA ABc | BGE E2 A/B/ | c2 c cde | dBG GAB | cBA GE^G | A3 [AA,]2 :| 
 e/f/ | g>ag gfe | dBG GBd | a>ba a>ba | gee e2 e | g>ag gfe | dBG GAB | cBA GE^G | A3 [AA,]2 :|  