Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:4/4
K:F
['cA F3 F F3 A AG G2']  
X:1
L:1/8
M:4/4
K:F
 cA | F3 F F3 A | AG G2 z2 FA | c3 cBABc | A4 z2 FF | d3 d f2 ed | dc c2 z2 Ac | c2 dc B3 E | 
 F4 z2 |]  