Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
M:4/4
K:A
['a2 ed', 'AcBA F2 AF EGBG']  
X:1
L:1/8
M:4/4
K:A
 a2 ed cAGA | F2 GA E2 (3efg | a2 ed cABc | dABc defg | a2 ed cAGA | FAGA Ee fg | a2 ed cABc | 
 dcBc BA bg :: a2 fa g2 eg | f2 df e2 cA | dBcd ABBE | DEdE cBAc | B2 GB AcBA | F2 AF EGBG |1 
 EBGB A2 z2 | f2 df ef g/f/e :|2 AcBA F2 AF | EGBG A2 z2 ||  