Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:3/4
K:G
['DGG B2 BA GD E3 (G/A/) BB']  
X:1
L:1/8
M:3/4
K:G
 DGG | B2 BA GD | E3 (G/A/) BB | B3 GB A- | A2 z BB B | d3 | Bdd | D2 z2 E2 | B3 AG D | E G2 ||  