Compose a piece using the alphabetic notation of the assigned musical structure and the provided melodic motif.
X:1
L:1/8
Q:1/2=80
M:2/2
K:G
['Bc d2 g4']  
X:1
L:1/8
Q:1/2=80
M:2/2
K:G
|: B2 A2 Bc d2 | g4 d2 e2 | =f2 c2 A2 f2 | =FGAB c2 A2 | B2 G2 Bc d2 | g4 b4 | b2 ag a2 gf | 
 g2 d2 B2 G2 |:  