Compose a piece of music by integrating the assigned letter representation and provided tune.
X:1
L:1/4
M:4/4
K:D
['F F', 'd d']  
X:1
L:1/4
M:4/4
K:D
 D | F F F E | F D D E | F A d A | B2 A z || B/c/ d d d | F G B A | A B A d | F/ E3/2 D2 ||  