Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
M:2/2
K:F
['C F2 Fc AFcA fc d/c/B/A/ BGGc', 'AFF c faeg dfcf BfAf Gggb afcf']  
X:1
L:1/8
M:2/2
K:F
 C | F2 Fc AFcA | fc d/c/B/A/ BGGc | AF FE/F/ CFAc | BGcB AFF :: c | faeg dfcf | BfAf Gggb | 
 afcf dfeg | fdcB AFFc | facf BfAf | cfaf egbg | afcf dbag | fdcB AFF :|  