Develop a musical piece employing the provided motif and an alphabet-based structure.
X:1
L:1/8
M:3/4
K:Amin
['(a2 .^g2) a2 e4 c2 (ed)(B^G)(BG)', '(A2 .c2) c2 (dc)BA ^G2']  
X:1
L:1/8
M:3/4
K:Amin
|: (a2 .^g2) a2 | e4 c2 | (ed)(B^G)(BG) | A2 c2 e2 | (a2 .^g2) a2 | e4 c2 | (ed)(B^G)(BG) | 
 A4 z2 :: (A2 .c2) c2 | (dc)BA ^G2 | (^G2 B2) d2 | (dc)Bc A2 | (A2 .c2) c2 | (dc)BA ^G2 | 
 (^GB)(dc)Bc | A4 z2 :|  