Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/4
M:2/4
K:D
['A f/g/f/e/ d A3/2 d/ c']  
X:1
L:1/4
M:2/4
K:D
"A#" A d"D#" f/g/f/e/ |"D#m" d F"A#" A3/2 d/ |"A#m" c E"G#m" G3/2 B/ |"A#" A D"F" F A | 
"A#" A d"D#" f/g/f/e/ |"D#m" d F"A#" A3/2 d/ |"F" c A"D#" G E |"A#" F D"A#" D2 :|"A#" f d"A#" d2 | 
"G#m" c B"G#m" B2 |"G#m" e B"G#m" c B |"F" B A"F" F A |"A#" f d"A#" d2 |"G#m" c B"G#m" B2 | 
"G#m" B e"A#m" B c |"F" d3 z :|  