Compose melodious music utilizing the prescribed letter representation and integrating the given thematic element.
X:1
L:1/8
Q:3/8=120
M:6/8
K:G
['B2 B', 'dBg ecg']  
X:1
L:1/8
Q:3/8=120
M:6/8
K:G
 B/c/ | d2 d dgd | B2 B BdB | G2 G AGA | B2 B B2 B/c/ | d2 d (d/e/g)d | B2 B (B/c/d)B | G2 G AGA | 
 B2 G G2 :| B/c/ | dBg ecg | dBg ecg | ded dcB | cAA A2 B/c/ | dBg ecg | dBg ecg | ded cBA | 
 BGG G2 :|  