Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
Q:1/4=140
M:4/4
K:Bb
['d>e f3 g f>d cB c>Bcd G3', 'B2 FE D3 F G>FGB c>Bcd G3']  
X:1
L:1/8
Q:1/4=140
M:4/4
K:Bb
 d>e | f3 g f>d cB | c>Bcd G3 B | F>GFD F2 BF | D2 G>G F2 B/c/d/e/ | f3 g{ab} (fdc)B | 
 ed cB G2 d>c | BG FD F2 B>c | d2 c>B B2 :: FE | D3 F G>FGB | c>Bcd G3 g | f>gfd ed cB | 
 e>f g/f/e/d/ c2 f>e | df ga b3{a} g | fd cB G2 d>c | BG FD F2 B>c | d2 c>B B2 :|  