Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:4/4
K:G
['e d c B']  
X:1
L:1/8
M:4/4
K:G
 E2 d e d c B A | E2 d e d c B A | G3 E B e d c | B A/ B/ A E G4 | F3/2 F/ E D B B2 d | 
 A3/2 B/ F E D4 | F4 E3/2 F/ D E | B A2 D G2 F E | D8 |]  