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
['(G>AG) (FE)D d3']  
X:1
L:1/8
M:6/8
K:G
"^Moderato" D | (G>AG) (FE)D | d3 (ef)g | (d>c)B (A2 G) | E3- E2 D | (G>AG) (FE)D | d3 (efg) | 
 (dcB) (A2 G) | G3- G2 d | (de)f g2 g | g3 (gf)e | (d>c)B (A2 G) | E3- E2 F | (G>AG) (FE)D | 
 d3 efg | (d>cB) A2 G | G3- G2 |]  