Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/16
Q:1/4=60
M:2/4
K:G
['BcdB cBcd']  
X:1
L:1/16
Q:1/4=60
M:2/4
K:G
 (3(DEF) |"G" G2GA BcdB |"C" cBcd e2(3(def) |"G" gfge dBGB |"D" cBAG FADF |"G" G2(GA) BcdB | 
"C"{d} cBcd e^deg |"D" bgdB{d} cAFD |"G" G2G2 G2 :: (3(def) |{a} gfga bgdB |"C"{d} cBcd ecAf | 
"G"{a} gfga bgdB |"C" cdef"G" g2(ga) |"G" (3(bag) fa (3(gfe) df | (3(edc) ge dBGB |"D" dgfg fdcA | 
"G" G2G2 G2 :|  