Construct a melodic piece using the designated alphabetic pattern and the provided musical theme.
X:1
L:1/4
M:3/4
K:G
['f g']  
X:1
L:1/4
M:3/4
K:G
 e | d B e | e2 e | d B G | F2 f | g f e | e ^d e | f d ^c | B2 f | g a g | f g e | 
 e/ d/ c/ B/ A/ G/ | F G A | B G E | F e ^d | e g f | e2 f | g a g | f g e | e/ d/ c/ B/ A/ G/ | 
 F G A | B G E | F e ^d | e g f | e2 ||  