Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:6/8
K:Amin
['c2 d', 'z a2 a- a^ga a2 e e2']  
X:1
L:1/8
M:6/8
K:Amin
 A | AGE G2 A | G2 E E2 D | EAA c2 d | e2 d de^f | g3 g^fe | dcB c2 d | edc BAG |{c} B2 A A2 :| | 
 z | a2 a- a^ga | a2 e e2 ^f | g2 a g2 e | dBG GBd | g2 g e2 e | dcB c2 d | edc BAG |{c} B2 A A2 :|  