Compose a musical piece using the designated musical pattern's alphabetic representation and the assigned melodic theme.
X:1
L:1/8
M:4/4
K:G
['BG G2', 'eg d2', '']  
X:1
L:1/8
M:4/4
K:G
 dc | BG G2 AGEG | BG G2 Bdgd | B3 G AGED | EAAG A2 GA | BG G2 AGEG | BG G2 Bdgd | B3 G AGED | 
 EG GF G2 :: Bc | dega bgag | eg d2 eg d2 | dega bgag | eaag a2 ge | dega bgag | eg d2 eg d2 | 
 B3 G AGED | EG GF G2 :| z8 ||  