Develop a musical piece that combines the given theme and letter-structured outline.
X:1
L:1/8
M:4/4
K:Amix
['a A<A B>A B<d e2 d>g B>g', 'A g a>ba>g b<a a2 g>ab>a g>ed>e']  
X:1
L:1/8
M:4/4
K:Amix
|: a | A<A B>A B<d e2 | d>g B>g A>G E2 | D<GB>G A>GB>G | D<D E>G B<A A :: g | a>ba>g b<a a2 | 
 g>ab>a g>ed>e | g>ag>e d>e g2 | e<gd>g B<A A :|  