Develop a musical composition based on the provided pattern of letters and incorporating the given motif within it.
X:1
L:1/4
Q:1/4=160
M:4/4
K:C
['A A/E/ A c B', 'B B/d/ c A']  
X:1
L:1/4
Q:1/4=160
M:4/4
K:C
 A A/E/ A c | B B/G/ B B | A A/E/ A c | B G A2 :| B B/d/ c A | B B/d/ c A | A A/E/ A c | B G A2 :|  