Develop a musical composition by integrating the alphabetically represented musical pattern and the supplied melodic theme.
X:1
L:1/8
Q:1/8=160
M:6/8
K:G
['D GBd dBe dBg dBA GBd dBG', 'G2 d gfg efg eag fed gfg']  
X:1
L:1/8
Q:1/8=160
M:6/8
K:G
 D | GBd dBe | dBg dBA | GBd dBG | DBA G2 D | GBd dBe | dBg dBA | GBd dBG | DBA G2 :| d | gfg efg | 
 eag fed | gfg edc | BAG d2 d | cec Bdg | dBG Adf | gdB dBG |1 DBA G2 :|2 DBA G3- | G6 ||  