Construct a music composition that complies with the designated structure and theme.
X:1
L:1/8
Q:1/2=80
M:2/4
K:D
['Gmaj in DFAF dFAF efge dcBA (D/E/F/G/)', 'fdfd gege cABc', 'd2 defd B2 ABAG F2 defd BcdB'  
X:1
L:1/8
Q:1/2=80
M:2/4
K:D
"_Key Gmaj in MS" DFAF | dFAF | efge | dcBA | (D/E/F/G/) AF | dFAF | GEAG | FD D :: f | fdfd | 
 gege | cABc | (d/c/d/e/) d>g | fdfd | gege | cABc | d2 d2 :: defd | cB"^tr" B2 | ABAG | 
 GF"^tr" F2 | defd | BcdB | AF (A/G/F/E/) | D2 D2 :|  