Write a musical work incorporating the specified theme and letter-based framework.
X:1
L:1/4
M:3/4
K:D
['B A']  
X:1
L:1/4
M:3/4
K:D
 F/E/ | D F G | A2 d/c/ | B A G | A z A | B A G | A2 A | B A G/E/ | F3/2 G/ A | F E D | E2 F/E/ | 
 D D E | F/>E/ D d/c/ | B A G | F/G/ A G | F3/2 D/ E | D2 |]  