Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/4
M:3/2
K:F
['F F']  
X:1
L:1/4
M:3/2
K:F
 C F F | F3 C _E D | C3 C F F | F3 C B A | G3 G A c | (A G2) F F D | (D C2) C F F | 
 F3 (3E/(D/C/) F F | F3 |]  