Develop a musical composition based on the provided pattern of letters and incorporating the given motif within it.
X:1
L:1/8
M:12/8
K:G
['B2 B BAB dBA G2 D', 'g3 gfe dcB c2 d']  
X:1
L:1/8
M:12/8
K:G
|: A | B2 B BAB dBA G2 D | GDG g2 e dBG A2 G | B2 B BAB dBA G2 D | Bdd B2 A G3 G2 :: d | 
 g3 gfe dcB c2 d | eaa a2 b a2 g e2 f | g3 gfe dcB c2 d | efg faf g3 g2 :|  