Compose melodious music utilizing the prescribed letter representation and integrating the given thematic element.
X:1
L:1/8
M:4/4
K:G
['gf g2 dB e2 cB AG', 'Bc dB e2 d2 cB AG']  
X:1
L:1/8
M:4/4
K:G
 gf g2 dB e2 | cB AG FG A2 | gf g2 dB e2 | cB AG DG G2 :: Bc dB e2 d2 | cB AG FG A2 | Bc dB e2 d2 | 
 cB AG DG G2 :|  