Craft a composition that integrates the assigned alphabet-related musical pattern and the provided melodic theme.
X:1
L:1/8
M:4/4
K:G
['dBAB G3', 'dB B2']  
X:1
L:1/8
M:4/4
K:G
 ge | dBAB G3 E | DG G2 DGBc | dBAB G3 A | Beed eage | dBAB G3 E | DG G2 DGBc | dBAB G3 A | 
 Beed e2 ge || dB B2 dBge | dB B2 d3 e | dB B2 gfgd | egdB A2 Bc | dB B2 gB B2 | edef gfga | 
 bgaf gfed | egfa gf ||  