Create a composition by utilizing the given alphabet-based musical pattern and the provided melodic theme.
X:1
L:1/8
M:6/8
K:Amix
['BAG E3', 'aAA gAA fAA eAA GB/c/d g3']  
X:1
L:1/8
M:6/8
K:Amix
|: BAG E3 | DEG A3 | BAG E3 | DEF GFE | BAG E3 | DEF G2 F | GB/c/d g3 | edB A3 :: aAA gAA | 
 fAA eAA | GB/c/d g3 | ede gfg | aAA gAA | fAA eAA | GB/c/d g3 | edB A3 :|  