Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:3/4
K:D
['d2 d2', 'g2 (3agf g2', 'B2 D2 DDDD |{d} c4 B2 f2', 'DDDD c4 B2 (3BAB (3cBc dF']  
X:1
L:1/8
M:3/4
K:D
 d2 d2 (3cde | d2 d2 (3efg | f2 f2 (3efg | f2 fagb |{b} a2 gfed |{d} c4 d2 | df/a/{a} g2{g} f2 | 
{f} e6 :: fg a2 gf | g2 A,B,CB, | A,2 efge | f2 DEFE | Da a4 | bgecdA | (3BAG F2 E2 |{E} D6 :| 
[M:3/4][K:G]"^Trio" !fermata!g2 g2 (3agf | g2 g2 (3agf | g2 GB dg |{d} c4 B2 | D2 DDDD |{d} c4 B2 | 
 f2 g2 aA | d6 :: d2 d2 ed | c2 eg b2 | c2 c2 Ac | BGBd g2 | D2 DDDD | c4 B2 | (3BAB (3cBc dF | 
 G6 :|  