Create a composition by utilizing the given alphabet-based musical pattern and the provided melodic theme.
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
['dc BGGF G2 dB cAAG A2 Bd', 'd2 Bd gdBG']  
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
 dc | BGGF G2 dB | cAAG A2 Bd | edgd edBG | BAAG A2 dc | BGGF G2 dB | cAAG A2 Bd | edgd edBA | 
 G2 GF G2 :| z B | d2 Bd gdBG | d2 Bd gdBG | d2 Bd gdBG | BAAG A2 dc | dGBd gdBG | dGBd g2 Bd | 
 efgf edBA | G2 GF G2 :|  