Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/4
M:3/4
K:C
['e/f/ d c A/G/ B']  
X:1
L:1/4
M:3/4
K:C
 g/^f/ a g | e/f/ d c | A/G/ B d | e/f/ d c | A/G/ B d | e/f/ a g | e/f/ d c | A/G/ B c |]  