Formulate a musical piece by utilizing the specified motif and alphabet-based structure.
X:1
L:1/8
M:6/8
K:Bb
['BAB (FBd) ecA BFA |{c} BAB FBd', 'gec fdB ecA fbf gec ecA B3', 'FBd ecA', 'fdB geg gec bgb bfd ecA']  
X:1
L:1/8
M:6/8
K:Bb
|: BAB (FBd) | ecA BFA |{c} BAB FBd | ecA B3 :: fbf gec | fdB ecA | fbf gec | ecA B3 :: FBd FBd | 
 ecA BFD | FBd FBd | ecA B3 :: fdf fdB | geg gec | bgb bfd | ecA B3 :|  