Craft a musical composition that incorporates the supplied alphabet sequence and motif.
X:1
L:1/8
M:3/8
K:G
['B/B/ BAG GFG AFc cBA AGA BGd']  
X:1
L:1/8
M:3/8
K:G
 B/B/ | BAG | GFG | AFc | cBA | AGA | BGd | BBB | BAG | d2 c | BBB | AAA | G2 |]  