Craft a musical composition that incorporates the supplied alphabet sequence and motif.
X:1
L:1/8
M:2/4
K:G
['BG Bd', 'z g>a gd']  
X:1
L:1/8
M:2/4
K:G
 BGBd | gd ec | BG Bd | cA/B/ A z | BG Bd | g dec | Bd GB | BG G z :: g>a gd | ag fd | eg dc | 
 BA/B/ A z | g>a gd | agfd | eg dc | BG G2 :|  