Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
M:6/8
K:D
['A, D2 E F2 G A2 d', 'A Bcd AGF EFD C,B,A, f2 f']  
X:1
L:1/8
M:6/8
K:D
 A, | D2 E F2 G | A2 d (dc)A | (Bc)d (AG)F | (EF)D C2 A, | D2 E F2 G | A2 d (dc)A | (Bc)d (ed)c |1 
 d3 d2 A, :|2 d3 d2 e || f2 f edc | d2 d c2 A | Bcd AGF | EFD C,B,A, | f2 f edc | ded dcA | 
 Bcd edc |1 d3 d2 e :| d3- d2 z2 ||  