Create a composition by utilizing the given alphabet-based musical pattern and the provided melodic theme.
X:1
L:1/8
M:4/4
K:G
['DG BG B/c/B/A/ BG DE/F/ GF G2', 'GA/B/ GA/B/']  
X:1
L:1/8
M:4/4
K:G
|:"G" DG BG B/c/B/A/ BG | DE/F/ GF G2 G2 |"D" A,>B, CE D2 D2 | A,>B, CE"G" D/E/D/C/ B,D | 
 DG BG B/c/B/A/ BG | DE/F/ GF G2 G2 |"D" A,>B, CE D2 D2 | D>F AB"G" G4 :: 
"G" B/B/B/B/ GD B/B/B/B/ G2 | ed d>B"D" cB A2 | A/A/A/A/ DF A/A/A/A/ F2 | ed d>c"G" BA G2 | 
 GA/B/ GA/B/ GA/B/ GA/B/ |"C" EF/G/ EF/G/ EF/G/ EF/G/ |"D" A2 A>B AG FE | D2 d/^c/d/e/ dD EF | 
"G" G z B z G4 :|  