Compose a piece of music by integrating the assigned letter representation and provided tune.
X:1
L:1/8
M:4/4
K:D
['A2 FA', 'd2 Ad f2 af gfed BcdB A2']  
X:1
L:1/8
M:4/4
K:D
|: AG | F2 DF A2 FA | d2 fd A2 FA | GBdB AFDF | E2 E>E E2 AG | F2 DF A2 FA | d2 fd A2 A2 | 
 BcdB cdec | d2 d>d d2 :: Ad | f2 af gfed | BcdB A2 (3ABc | dAdA dAFD | E2 E>E E2 AG | 
 F2 DF A2 FA | d2 fd A2 A2 | BcdB cdef | d2 d>d d2 :|  