Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
Q:1/2=90
M:4/4
K:C
['B,BdB FAcA Bdfd egec dfdB', 'dfbf dfbf edcB']  
X:1
L:1/8
Q:1/2=90
M:4/4
K:C
 C |[K:Bb]"^MS 40 p 39" B,DFD B,BdB | FAcA Bdfd | egec dfdB | cBAG FEDC | B,FDF B,BdB | FAcA Bdfd | 
 egec dfdB | GecA B2 z2 || dfbf dfbf | dfbf edcB | dfbf dfbf | edcB A2 Bc | dfbf dfbf | edcB AcAF | 
 egec dfdB | GecA B2 B2 :|  