Create music using the given musical theme and adhere to the outlined letter-based structure.
X:1
L:1/8
M:6/8
K:Bb
['B,BB A,cc B,dd Cee', 'B3 eca bfd ecA BFD Egf fed']  
X:1
L:1/8
M:6/8
K:Bb
|: B,BB A,cc | B,dd Cee | def ged | cdB AGF | B,BB A,cc | B,dd Cee | d2 e fed | cBA B3 :: eca bfd | 
 ecA BFD | Egf fed | cdB AGF | dBB, e2 C | fdD E2 g | f2 e dcB | cBA B3 :|  