Write a musical work incorporating the specified theme and letter-based framework.
X:1
L:1/4
M:6/4
K:Bb
['c F2 B3- B2', 'f d']  
X:1
L:1/4
M:6/4
K:Bb
 B | B3 c F2 | B3- B2 (d/c/) | B2 (e/d/) c F2 | B3- B2 f | d2 g f2 b | a f2 b2 a | g a f g c2 | 
 f3- f2 :: f | f2 c f2 B | f d B f2 d | g f d e G c | =B3 c2 f | d B b a2 g | f d g f2 d | 
 e c A f d2 | c3 B2 |]  