Compose a musical piece using the designated musical pattern's alphabetic representation and the assigned melodic theme.
X:1
L:1/8
M:2/4
K:G
['ddee ddcA BBBD GABc']  
X:1
L:1/8
M:2/4
K:G
 D | GGBB | ddee | ddcA | BBBD | GABc | ddee | ddcA | BBBD | GABc | d2 e2 | ddcd | B2 z |]  