Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:2/4
K:G
['BdAB GFED E2', 'G3 B c>Bcd e2 (B>c) dBAG A2']  
X:1
L:1/8
M:2/4
K:G
 G | BdAB | GFED | E2 A>B | A2 G>A | BdAB | GFED | E2 (G>A) | G3 :: B | c>Bcd | e2 (B>c) | dBAG | 
 A2 G>A | BdAB | GFED | E2 G>A | G3 :|  