Create a composition by utilizing the given alphabet-based musical pattern and the provided melodic theme.
X:1
L:1/8
Q:1/2=80
M:4/4
K:G
['g fdec (d/c/B/c/) d2 FDDF A2 Ag', 'c (B/c/d)', 'c BGAF BGAF', 'defg afdf']  
X:1
L:1/8
Q:1/2=80
M:4/4
K:G
 g | fdec (d/c/B/c/) d2 | FDDF A2 Ag | fdec B3/2(A/4B/4) c2 | ECCE G3 :: c | (B/c/d) DF AFDc | 
 (B/c/d) DF A3 c | (B/c/d) DF(AB) cA | GECE G3 :: c | BGAF BGAF | FDDF A3 c | BGAF BGAF | 
 ECCE G3 :: A | defg afdf | gfdf a2{g} f2{e} | defg afdf | gece g2 f>d | G3 :|  