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
M:6/8
K:D
['Add dcd efe efg fed dcd', 'd3 dfa afd Bgf gec ddd dcd']  
X:1
L:1/8
M:6/8
K:D
 Add dcd | efe efg | fed dcd | ecA d3 :: dfa afd | Bgf gec | ddd dcd | ecA d3 :|  