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>ed<c B2 b2 a>ba<f d>ef<a', "b>ag<f g>ed<A F>Ad<f f<aa>b a<c'c'<f f<aa>f"]  
X:1
L:1/8
M:2/2
K:G
 DG>A | B>DG<A B>DG<B | d>ed<c B2 b2 | a>ba<f d>ef<a | g>ed<c B>AG>F | G>FG>B d>DG<B | 
 d>ed<c B2 b2 | a>ba<f d>ef<a | g>gg>f g :: z g>a | b>ag<f g>ed<A | F>Ad<f f<aa>b | 
 a<c'c'<f f<aa>f | g>gg<b b>ag>a | b>ag<f g>ed<A | F>Ad<f f<aa>b | a<c'c'<f f<aa>f | g>gg>f g :|  