Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/16
Q:1/4=100
M:2/4
K:D
['DEFG A2d2']  
X:1
L:1/16
Q:1/4=100
M:2/4
K:D
|: DEFG A2d2 | B2e2 dcBA | DEFG A2d2 | B2c2 d4 |:  