Construct a melodic piece using the designated alphabetic pattern and the provided musical theme.
X:1
L:1/8
M:6/8
K:D
['B2 A F2 A AB=c B^AB G3', 'f2 d']  
X:1
L:1/8
M:6/8
K:D
|: B2 A | F2 A AB=c | B^AB G3 | BGE E2 G | AFD D2 G | FAA AA/B/=c | B^AB G2 =A | Bcd e2 A | d2 A :: 
 B2 g | f2 d fdf | e2 c ec/d/e | f2 d fd/e/f | a^ga b2 =g | fdf f2 A | ece e2 A | BB/c/d e2 A | 
 d3 :|  