Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:6/8
K:G
['A2 B c2 d']  
X:1
L:1/8
M:6/8
K:G
 d | c2 B A2 D | F2 G A2 B | c2 d e2 d | c3- c2 c | B2 A B2 c | ded A2 B | c2 d B2 A | G3- G2 |]  