Create a composition by utilizing the given alphabet-based musical pattern and the provided melodic theme.
X:1
L:1/8
Q:1/8=150
M:2/2
K:D
['B2 B2 dB', 'defg abaf']  
X:1
L:1/8
Q:1/8=150
M:2/2
K:D
 fe | d2 B2 B2 dB | AFAB ABde | f2 B2 B2 dB | ABde fefa | b2 B2 B2 dB | A2 AB ABde | f2 B2 B2 dB | 
 ABde f2 :| fe | defg abaf | defg a2 af | defg abaf | edef g2 fe | defg abaf | defg a2 gf | 
 gfga bagf | edef g2 :|  