Construct melodies utilizing the provided motif and adhere to the outlined musical structure.
X:1
L:1/8
M:2/4
K:Bb
['', 'ca cf', 'B2 cb'  
X:1
L:1/8
M:2/4
K:Bb
 d>e |:"Bb" fd' bg | f2 d>e | fd' bg | f2 b2 |"F7" ac' ag | fb ac' |1"Bb" bd' bg | f2 d>e :|2 
"Bb" b4 | b2 z x4 |][K:F][M:3/4]"F" ca cf Ad |"C7" cb ce B2 | cb ce Bd |"F" ca cf A2 | ca cf Ad | 
"C7" cb ce B2 | cb ce Be |"F" f6 |"F" ca cf Ad |"C7" cb ce B2 | cb ce Bd |"F" ca cf A2 | ca cf Ad | 
"C7" cb ce B2 | cb Bg Ge |"F" f6 |]  