Construct a musical piece by amalgamating the designated alphabetical representation and the supplied musical theme.
X:1
L:1/8
M:6/8
K:Dmix
['F3 AGG AFD GED DED']  
X:1
L:1/8
M:6/8
K:Dmix
 F3 AGG | AFD GED | DED c2 A | ded cAG | F3 AGG | AFD GED | DED GED |1 DED D2 E :|2 DED D2 B ||  