Develop a musical composition by integrating the alphabetically represented musical pattern and the supplied melodic theme.
X:1
L:1/8
M:2/2
K:G
['GdBG FdAF GdBG D2 GF', 'AG FAd^c']  
X:1
L:1/8
M:2/2
K:G
 (3DEF | GdBG FdAF | GdBG D2 GF | EGAB cBAG | Fd^cd ed=cA | GdBG FdAF | GdBG D2 GF | EGce dBGB | 
 ADFA G2 :| AG | FAd^c d2 AG | FAd^c dfed | ^cdef g2 fe | d^cde d3 =c | BcBA ^GB e2 | ABAG FA d2 | 
 egfe dcBA | G2 FA G2 :|  