Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
M:3/4
K:F
['f2 gf/g/ ac d2 ed/e/ fA Bd/c/', 'F4 cf fa ac d/c/B/A/ B4 dg']  
X:1
L:1/8
M:3/4
K:F
 f2 gf/g/ ac | d2 ed/e/ fA | Bd/c/ BA GF | E/F/G/E/ F4 :: cf fa ac | d/c/B/A/ B4 | dg gb bf | 
 e/f/g/a/ g/f/e/d/ e"^Da capo" c :|  