Assemble a piece of music by merging the alphabetic representation of the predetermined musical pattern and the provided melodic theme.
X:1
L:1/8
Q:1/4=90
M:2/4
K:Emin
['GA |[M:3/4] B2', 'BB [M:2/4] A2 FG']  
X:1
L:1/8
Q:1/4=90
M:2/4
K:Emin
 BB Bd | B2 GA |[M:3/4] B2 GA BB |[M:2/4] A2 FG | E4 :: G>F EE | D2 GA |[M:3/4] B2 GA BB | 
[M:2/4] A2 FG | E4 :|  