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:D
['GB AG', 'ec Ac ec']  
X:1
L:1/8
M:4/4
K:D
 (3ABc | dA FA GB AG | FE DF GB AG | FE DF GB AG | FE DF E2 (3ABc | dA FA GB AG | FE DF GB AG | 
 FA df ge ce | df ec d2 :: d2 | ec Ac ec ge | fd Ad fd af | ec Ac ec fe | dc Bc (3BAF A2 | 
 BG DG BG dB | AF DF dc dB | Ac ef ge ce | df ec d2 :|  