Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:4/4
K:D
['f>e e<d']  
X:1
L:1/8
M:4/4
K:D
 A>F |"D" D2 D>F A2 A>B |"D" d>e f>e e<d d>B |"D" A>B d>B"Bm" A<F F>D |1"Em" E>D E>F"A7" E2 :|2 
"A7" E>D E>F"D" D2 |] A2 |"D" d2 f>e e<d d>A |"G" B2 d>B"D" A<F F>G |"D" A<F{F} E>D"Bm" D<d d>B | 
"Em" A<F F>D"A7" E2 |] f>g |"D" a>g f/e/d/c/ e<d d>A |"G" Bg/f/ e/d/c/B/"A7" A2 F>G | 
"D" A2 B>A"Bm" (3ABd a>g |"A7" f2 e>d"D" d2 |]  