Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/4
M:2/2
K:Dmix
['B A', 'd3 f2 a g/f/ e A2- A']  
X:1
L:1/4
M:2/2
K:Dmix
|: D2 F E/D/ | A d2 B | A E2 F | G/A/ B2 c | d B A F | G E g2 | B G F E | D d3 :: f2 a g/f/ | 
 e A2- A | B2 d c/B/ | A F2 F | G A B c | d B g2 | B G F E | D d3 :|  