Construct a musical composition following the given alphabetical structure and incorporating the specified motif.
X:1
L:1/8
M:2/4
K:G
['dB GB AB A2- Af', 'A2- Af']  
X:1
L:1/8
M:2/4
K:G
|: dB GB | AB A2- | Af ef | ed BB/c/ | dB GB | AB A2- | Af ed |1 BA GB/c/ :|2 BA G2 |: G2 g2 | 
 fg A2- | Af ef | ed BB/c/ | dg gg | fg A2- | Af ed |1 BA G2 :|2 BA GB/c/ ||  