Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/4
Q:1/2=120
M:6/4
K:Gmin
['B A2', 'G2 A/B/ c2 z A F z']  
X:1
L:1/4
Q:1/2=120
M:6/4
K:Gmin
 g/^f/ | g3/2 a/ b a2 g | ^f3/2 g/ a d2 g | f d B (d/e/ f) B | A2 B c2 d | e d c d c B | 
 A2 f (A/B/ c) A | B D G (^F/G/ A) ^F | G3- G2 :: A/B/ | c2 z A F z | f2 z d B g | f B c c2 B | 
 B3- B2 f | d g2"^*" =e2 c | =e a2 ^f d ^f | g d b g2 ^f | g3- g2 :|  