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:Amix
['ABdA B2 AB', 'f2 d<e e2 de f2 ef dBBa']  
X:1
L:1/8
M:4/4
K:Amix
 e | ABdA B2 AB | d2 fe dBBe | ABdA B2 AB | e<efB AAA :| a | f2 d<e e2 de | f2 ef dBBa | 
 f2 d<f e2 dB | d<efB AAAa | f2 d<e e2 de | f2 ef dBBa | f2 ed e2 dB | d<efB AAA |]  