Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/4
M:4/4
K:C
['G A']  
X:1
L:1/4
M:4/4
K:C
 G2 | E3/2 E/ E3/2 E/ | E3 C | D3/2 C/ D E | F2 G2 | E3 G | E G G G | A3 G | c3/2 G/ G3/2 E/ | 
 E D2 C | D C D E | F2 G2 | E3/2 D/ E F | G3 G | A G A B | c G A G/F/ | G2 G2 | E2 |]  