Construct a musical composition utilizing the provided motif and conforming to the specified structure.
X:1
L:1/8
M:4/4
K:G
['', 'cB AG FG AF GABG', 'B cB cd e4 g4 ag fe'  
X:1
L:1/8
M:4/4
K:G
 AB |: cB AG FG AF | GABG A2 D2 | F2 D2 FG A2 A3 B cB AG | FG AF GABG | ABcd B2 G2 | G3 B :: 
 cB cd e4 | g4 ag fe | defd efge | a2 A2 A3 B | cB cd e4 | g4 ag fe | defd AB cd |1 B2 G2 G3 B :|2 
 B2 G2 G2 |]  