Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/4
M:4/4
K:G
['a/ g f/e/ d/e/f/g/ a3/2 f/ g', 'c e e d/c/ B d d']  
X:1
L:1/4
M:4/4
K:G
 d | g3/2 a/ g f/e/ | d/e/f/g/ a3/2 f/ | g d e d/c/ | B G G d | g a/ g f/e/ | d/e/f/g/ a3/2 f/ | 
 g d e d/c/ | B G G |: z | c e e d/c/ | B d d c/B/ | A e d c | B/c/d/B/ G B | c e e d/c/ | 
 B d d g | f/g/a/f/ e f | g g g :|  