Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:2/2
K:Amix
['e2 Ac', '(dB)GB (vcB)ce (cA)AB (cB)ce (dB)GB (cB)ce (cA)cA']  
X:1
L:1/8
M:2/2
K:Amix
|: ve2 Ac (ec)Aa | e2 Ac (dB)GB | e2 Ac (eA)cA | (BE)Be (dB)GB :: (vcB)ce (cA)AB | (cB)ce (dB)GB | 
 (cB)ce (cA)cA | (BE)Be | (dB)GB :|  