Create a musical composition based on the alphabetic representation of the predetermined pattern and the given melodic theme.
X:1
L:1/8
M:2/4
K:Ab
['ABec B3 c/B/']  
X:1
L:1/8
M:2/4
K:Ab
 ABec | B3 c/B/ | ABec | B3 c/B/ | ABcB/c/ | AA F4 AAB/A/F | E3 F/E/CzEFAFE(3E/F/E/ | CEFE/F/CC | 
 B,4 z2 |]  