Assemble a piece of music by merging the alphabetic representation of the predetermined musical pattern and the provided melodic theme.
X:1
L:1/4
M:6/4
K:G
['z3 d d2 g']  
X:1
L:1/4
M:6/4
K:G
 B | d2 d d B A | G2 B B B d | A2 B c d3/2 c/ | c B z3 d | d2 g g2 g | g a g f d c | B2 d g2 B | 
 e d z3 d | d2 g b2 a | a g z3 |]  