Develop a musical composition by integrating the alphabetically represented musical pattern and the supplied melodic theme.
X:1
L:1/8
Q:3/8=90
M:6/8
K:A
['a3 c2 d', 'B3 c3 BGE']  
X:1
L:1/8
Q:3/8=90
M:6/8
K:A
 e3{g} a3 | c2 d ecA | BGE BGE | ecA BGE | e3 a3 | c2 d efg | agf gab | Be^d e3 :: B3 c3 | 
 BGE BGE | ecA BGE | ecA BGE | B3 c3 | BGE efg | agf ega | cdB A3 :|  