Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:2/4
K:C
['FD DB, C2 C2']  
X:1
L:1/8
M:2/4
K:C
"C" GE"G7" FD |"C" EC"G" DB, |"C" C2 C2 |"C" C4 |"F" AA AA |"F" AB cA |"C" G2 G2 |"C" G4 | 
"F" AA AA |"F" AB c2 |"C" GA GF |"C" ED C2 |"C" GE"G7" FD |"C" EC"G" DB, |"C" C2 C2 |"C" C4 |]  