Develop a musical composition using both the specified melodic theme and the alphabetical pattern naming.
X:1
L:1/8
M:12/8
K:Amix
['e2 A', 'a2 g']  
X:1
L:1/8
M:12/8
K:Amix
|: AB/c/d | e2 A c2 A e2 A d2 f | e2 A cBA dcd f2 a | e2 A cBA ecA d2 f | efe dd/c/B A3 :: Ace | 
 a2 g e2 a g2 e d2 b | a2 g ee/f/g a^ga b2 g | a2 g ef/g/a g2 e d3 | e^de =dcB A3 :|  