Construct a melodic piece using the designated alphabetic pattern and the provided musical theme.
X:1
L:1/8
M:2/4
K:G
['BG GA/B/ cA']  
X:1
L:1/8
M:2/4
K:G
 G/A/ |"G" BG GA/B/ |"D" cA A(d/c/) |"G" BG"D" AF |"G" G3 :: B/c/ |"G" dd dg |"C" ec cc/d/ | 
"Am" ee ea |"D" fd dd/c/ |"G" BG GA/B/ |"D" cA Ad/c/ |"G" BG"D" AF |"G" G2 z :|  