Construct a musical piece by amalgamating the designated alphabetical representation and the supplied musical theme.
X:1
L:1/4
M:3/4
K:G
['e d', 'a g']  
X:1
L:1/4
M:3/4
K:G
 d | d g f | d f e | d e d |"^^" B2"^^" B | d c ^G | A d c | B/A/ G2- | G d d | d g f | d f e | 
 d e d | B2 B | d c ^G | A d c | (B/A/) G2- | G2 |] ud | e a g | _e a g | d a g | d2 d | ^c d e | 
"^^" f2"^^" f | f3- | f e d | d g f | d f e | d e d | B2 B | d c A | d e f | 
"_D.C. to Allegro." g3- | g z |]  