Compose melodious music utilizing the prescribed letter representation and integrating the given thematic element.
X:1
L:1/8
M:2/4
K:D
['A2 AA', 'fgfe f2 d2 e2 c2']  
X:1
L:1/8
M:2/4
K:D
 A2 AA A2 AA | B2 BB B2 BB | e2 ee e2 fe | dcBc d2 z2 :| fgfe f2 d2 | e2 c2 defg | fgfe f2 d2 | 
 e2 c2 d2 z2 :|  