Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
['D3 G', 'G2 Bddg']  
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
 D3 G B2 Ac | BG{AGF} G2 AEGE | D3 G BABc | dBAG EAGE | D3 G B2 Ac | BG{AGF} G2 AEGE | DEGA BABc | 
 dBAG EG G2 || Bddg ed g2 | BddB AGEG | Bddg edgd | (3BcB Ac BG G2 | Bddg edgd | BddB AG E2 | 
 Bddg egdg | (3BcB Ac BGGE |]  