Construct a melodic piece using the alphabet-based musical sequence and the given motif.
X:1
L:1/8
M:2/2
K:Bb
['BDGB AD^FA (GD)GB (dc)BA', 'FBEB (DF)Bd (fb)fd']  
X:1
L:1/8
M:2/2
K:Bb
 (dc) | BDGB AD^FA | (GD)GB (dc)BA | (Bd)gf (ed)cB | AGFE D(cBA) | BDGB AD^FA | (GD)GB (dc)BA | 
 f=e_ed cBAG | FEDC B,2 :: (FE) | DGEG FBEB | (DF)Bd (fb)fd | Ec=Ec FcGc | (Ac)ec (AF)EC | 
 DBEB FBEB | (DF)Bd (fb)fd | f=e_ed cBAG | FEDC B,2 :|  