Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:4/4
K:F
['F2 A2 c2 dc B2 G2 F2']  
X:1
L:1/8
M:4/4
K:F
 F2 A2 c2 dc | B2 G2 F2 C2 | FFAA c2 BA | G4 z4 | F2 Bd f2 ed | c2 fc A2 F2 | GFEG d2 cB | A4 z4 |]  