Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/16
M:2/4
K:D
['A4 B2A2 ABcA d4 E2ED', 'c2cB A2F2 A2BA GFGA d2dc B2D2 B2DG']  
X:1
L:1/16
M:2/4
K:D
 A4 B2A2 | ABcA d4 | E2ED GEED | E2ED GEDE | A4 B2A2 | ABcA d4 | E2ED G2E2 |1 D4 D4 :|2 D4 D2dc || 
[K:G] B2D2 B2DG | B2B2 c2cB | A2F2 A2BA | GFGA d2dc | B2D2 B2DG | B2B2 c2>B2 | ABAG FDEF |1 
 G4 G2dc :|2 G4 G4 ||  