Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:4/4
K:D
['D2 F>A d>AF>D', 'd>fa>f g>fe>d']  
X:1
L:1/8
M:4/4
K:D
 A, | D2 F>A d>AF>D | E>Be>d c>A (3Bcd | D2 F>A d>AF>D | A,>EC>E F<D D :| A | d>fa>f g>fe>d | 
 c>Ae>A f>Ae>A | d>fa>f g>fe>d | c>ba>g f<dd>A | d>fa>f g>fe>d | c>A (3AAA f>Ae>A | d>fa>f g>fe>d | 
 c>ba>g f<dd>A ||  