Create a composition by utilizing the given alphabet-based musical pattern and the provided melodic theme.
X:1
L:1/4
M:4/4
K:G
['B A G', 'e d']  
X:1
L:1/4
M:4/4
K:G
 d/c/ | B A G d/c/ | B A G g | e3/2 d/ c e | d3/2 c/ B d | c B A G F/G/A/F/ D d/c/ | 
 B/A/B/G/ A F G2 G :| e3/2 e/ e d | e f g2 g f e d | B/A/G/B/ A2 | G G A3/2 A/B/A/ G g3/2 f/ | 
 g d e2 | d B c2 | c B A G | F/G/A/F/ D d/c/ | B/A/B/G/ A F | G2 G ||  