Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:2/4
K:A
['z AA B']  
X:1
L:1/8
M:2/4
K:A
 A | A2 A G- | G2 GG | F2 (FE) | C4- | C4 | z AA B | c c3 | (GA) B2 | z AA B | c3 c | B2 GF | E4- | 
 E4 | z2 FF | E C3- | C2 CB, | C4 | F4- | F3 ||  