Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
Q:3/8=120
M:6/8
K:Bb
['f2 d Bdf fec dBF FGA Bcd', 'd cfe d2 c B2']  
X:1
L:1/8
Q:3/8=120
M:6/8
K:Bb
 f2 d Bdf | fec dBF | FGA Bcd | fec A2 F | f2 d Bdf | fec dBF | FGA Bcd | e z c B2 F!fine! :| 
 !fermata!e2 d cfe | d2 c B2 d | cAA FGA | BdB F2 F | e2 d cfe | d2 c B2 c | A2 A{A} GFG | 
 FcA fca!D.C.! |]  