Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:6/8
K:D
['', 'f2 e']  
X:1
L:1/8
M:6/8
K:D
 A |:"D" D>ED F>GF | A>BA"A" f2 e |"D" d>AF"G" G>AB |"D" A<dF"A" F>ED |"D" D>ED"F#m" ABA | 
"Bm" d>ed"G" a2 g |"D" f>dA"G" B>cd |"A" A<BA"D" F>ED |"D" F2 G A2 d |"A/C#" f>ed e2 A/G/ | 
"Bm" F2 f"E" f>ed |"A" c2 d e>AG |"D" F2 d d>cB |"Bm" F2 g f2 e |"G" f>dA B>cd |1"A" A<BA F>ED :|2 
"A" A<dc"D" d2 ||  