Compose a musical piece using the designated musical pattern's alphabetic representation and the assigned melodic theme.
X:1
L:1/8
M:6/8
K:G
['GFG AGF GBd def', 'dBd gbg ece a2 g faf def']  
X:1
L:1/8
M:6/8
K:G
 GFG AGF | GBd def | g2 e d2 G | FAG FED | GFG AGF | GBd def | gfg dba | g2 g2 :| dBd gbg | 
 ece a2 g | faf def | gfg bgd | dBd gbg | ece a2 g | faf def | g2 g2 :|  