Craft a composition that integrates the assigned alphabet-related musical pattern and the provided melodic theme.
X:1
L:1/8
M:6/8
K:G
['A/G/ A>_Bc/A<BA/G/B/ AGF']  
X:1
L:1/8
M:6/8
K:G
 A | AGAAGA | _B/c/dc/B/ A2 A/G/ | A>_Bc/A<BA/G/B/ | AGF G2 _B | A>GA/G<=FG/A | G=FE F2 A/G/ | 
 A>_Bc/A<BA/G/B/ | AGF G2 |]  