Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:3/4
K:G
['', 'GA B2', 'Bd e2 eg ab (g2 g)d ed']  
X:1
L:1/8
M:3/4
K:G
 DG/A/ |: B2 Bd BG | E2 D2 GA | B2 Bd GB | A2 A2 GA | B2 BG AG | E2 D2 GA | B2 BG AG |1 
 G2 G2 DG/A/ :|2 G2 GA Bd |: e2 eg ed | B2 BA Bd | e2 eg ab | (g2 g)d ed | B2 Bd BG | E2 D2 GA | 
 B2 BG AG |1 G2 GA Bd :|2 G2 G2 DG/A/ ||  