Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:2/2
K:G
['d>^cd>f g>e=c>A G>FG>B D2 E>F', 'G2 F>G A>GA>B c>Bc>d e>de>f g2 g>f']  
X:1
L:1/8
M:2/2
K:G
 B>c | d>^cd>f g>e=c>A | G>FG>B D2 E>F | G>FG>A B>AB>c | d>^cd>g A2 B>=c | d>^cd>f g>e=c>A | 
 G>FG>B D2 E>F | G>ed>c B>AG>F | G2 B2 G2 :: F>G | A>GA>B c>Bc>d | e>de>f g2 g>f | e>dc>B c>BA>G | 
 F2 D2 D2 B>c | d>^cd>f g>e=c>A | G>FG>B D2 E>F | G>ed>c B>AG>F | G2 B2 G2 :|  