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:G
['G>A BB', 'BB gg d2']  
X:1
L:1/8
M:2/4
K:G
 G>A BB | G>A BB | c/d/c/B/ AA | B/A/B/c/ BA | G>A BB | G>A BB | c/d/c/B/ A/B/A/F/ | GG G2 :: 
 d>c BB | gg d2 | d/e/d/c/ BB | gg d2 | G>A BB | G>A BB | c/d/c/B/ A/B/A/F/ | GG G2 :|  