Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
M:4/4
K:G
['ABBA d2 cA BGGG', 'g2 fd']  
X:1
L:1/8
M:4/4
K:G
 ABBA d2 cA | BGGG dcBG | ABcA dcAd | ddcA BGGG | ABBA d2 cA | BGGG dcAB | GBBB GBeg | 
 dBAc BG G2 :| fgaf g2 fd | dcAc d^cdg | feaf g2 fd | dBAc BGGg | fgaf g2 fd | dcAc d^cdg | 
 f3 a agfg | a2 ag fedc :|  