Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:4/4
K:C
["e>f g>c' b>a g2 e2"]  
X:1
L:1/8
M:4/4
K:C
 (3GAB |"C" c>B c>G E>G A>B | c2 (3ccc c2 (3cde |"F" f>e f>d"C" e>d e>c |"G" (3Bcd (3cBA G2 (3GAB | 
"C" c>B c>e"G" d>c B>e |"F" f2 (3fff f2 (3def |"C" e>c B>A"G7" G>f e>d |"C" c2 (3ccc c2 e>f | 
 g>c' b>a g2 e2 | (3gag f>e"G" f2 d>e | f>b a>g f2 d2 |"C" e>d (3cde"G" g2 e>f | 
"C" g>c' b>a g2 e2 |"F" (3d^cd (3fef a3 a |"G7" g>a b>a g>f e>d |"C" c>c"F" c>B"C" c2 ||  