Best get some recordings of Quebecois to see what's up.
Any tune that departs from the usual 4x32 form can be called "crooked". One of
the ways that I have Quebecois musicians usually make a tune crooked is by playing the
introductory notes of a tune in its own measure instead of grouping them in the last
measure of the tune.
Think of the Star Spangled Banner. If you were to sing the first stanza over and over
again, you'd sing it like:
LAN-AND OF the | FRE-EE AND the | HOME OF THE | BRAVE ___ OH-oh | SAY CAN YOU
A Quebecois musician would do this:
LAN-AND OF the | FRE-EE AND the | HOME OF THE | BRAVE ___ ___ | ___ ___ OH-oh } SAY CAN
YOU
but they'd do it with jigs and reels. I have worked with musicians that swear up and
down they are playing straight tunes when they actually are not. If you are unsure, it
would be best if you can do a dry run with the musicians before the dance to alert them of
your needs. If the musician is flexible, they can do what you need.
Good luck!