Create a musical composition employing the given alphabetic structure and melodic theme.
X:1
L:1/8
Q:1/2=80
M:2/2
K:G
['D3 E G3 A BABd', 'G2 d2 gfga b2 ag fefg a2', 'DEDE GEGA BABc', 'G2 d2 gdfa b2 ag fefg a2']  
X:1
L:1/8
Q:1/2=80
M:2/2
K:G
"_key D in ms" (GF/E/) | D3 E G3 A | BABd B2 AG | F3 E DEFG | AFdF EFGE | D3 E G3 A | BABd e3 g | 
 B2 AG AGAc | B2 G2 G2 :: d2 | gfga b2 ag | fefg a2 gf | edef gfed | B2 e2 e2 g2 | dBAG d2 cB | 
 edef g3 a | B2 AG AGAc | B2 G2 G2 :: GE | DEDE GEGA | BABc BdcB | AGAB cBcd | edef ga b2 | 
 DEDE GEGA | BABc e2 B2 | B2 AG BAGA | B2 G2 G2 :: d2 | gdfa b2 ag | fefg a2 gf | edef gfed | 
 B2 e2 e2 G2 | Bd g2 Bd e2 | Ad d2 Gc c2 | B2 AG BAGA | B2 G2 G2 :|  