Craft a composition that integrates the assigned alphabet-related musical pattern and the provided melodic theme.
X:1
L:1/8
M:12/8
K:G
['d2 B', 'd e2']  
X:1
L:1/8
M:12/8
K:G
 A | B2 B BAB d2 B G2 A | B2 d g2 e d2 B A2 c | B2 B BAB d2 B G2 A | Bcd cBA (G3 G2) :: d | 
 g2 g gfe d2 B c2 d | e2 a a2 b a2 g e2 f | g2 g gfe d2 B c2 d | e2 d e2 f (g3 g2) :|  