Construct a musical piece by amalgamating the designated alphabetical representation and the supplied musical theme.
X:1
L:1/8
M:6/8
K:G
['gfe dBG', 'd g/a/ba']  
X:1
L:1/8
M:6/8
K:G
 (3(d/e/f/) | gfe dBG | cBc def | gfe dBG | cAA A2 (3d/e/f/ | gfe dBd | eag fef | gfe dBA | 
 BGG G2 :: d | g/a/ba gdc | Bdd d2 e/f/ | g/a/bg dBd | eaa a2 d | g/a/ba gBd | egf gba | gfe dBA | 
 BGG G2 :|  