Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
Q:1/4=160
M:4/4
K:D
['E2 BA', 'f2 af']  
X:1
L:1/8
Q:1/4=160
M:4/4
K:D
|: D2 | E2 BA FAFA | defe cAFD | E2 BA FAGA | Adef gecA | E2 BA FAGA | BAGA BAcA | Adef gecB | 
 A2 d2 d2 :: e2 | f2 af gecA | DFAd efge | f2 af gfed | cAce g2 f2 | f2 af gecA | DFAd efge | 
 fdge fdec | dBAF D2 :|  