Develop a musical composition by integrating the alphabetically represented musical pattern and the supplied melodic theme.
X:1
L:1/8
M:4/4
K:G
['', 'cAFA G2', 'B2 ef']  
X:1
L:1/8
M:4/4
K:G
 AG |: FGAF BDB,D | GBAc BGGA | B^cdf eB=cA | E2 AG FDB,D | (3GGG BG AGBG | GABc defg | 
 (3agf ge defd |1 cAFA G2 AG :|2 cAFA G2 GA || B2 ef gfed | (3BcB GB ABGA | B2 ef gfga | 
 (3bag (3agf gfed | B2 ef gfed | eBBA B^cdf | (3efg fa gbaf |1 gedB G2 GA :|2 gedB G2 AG ||  