It's fun to see the creative ideas for dances with odd numbers.
In my experience, awkwardly small groups often occur at the beginning
or end of a regular evening (or at the mid-afternoon contra session
on a hot summer day).
In such circumstances, it's nice to have material that requires
minimal teaching, and gets people moving to music quickly. Bonus
points if it can accommodate dancers showing up late and adding-in.
Consistently successful for me is Steve Zakon-Anderson's well-known
contra 3-33-33. The opening is a continuous loop that works just fine
with 4 couples [you're never "out" -- just treat partner as next
neighbor and keep rolling-- get a rest in the Bs]. It's also workable
with 3 couples, or 5 (really,any number). In these circumstances, I
replace the final do-si-do with a chain --- a much more reliable transition ...
https://www.ibiblio.org/contradance/thecallersbox/dance.php?id=3259
We discovered the felicity of this dance about 20 years ago -- in a
hot afternoon class at Buffalo Gap. Dancers liked it so much they
requested repeats at subsequent sessions. In the intervening years, I
have turned to it whenever it feels 'right' for a small, but fairly
experienced group. Feedback has been consistently positive.
My hunch is that more than a few familiar contras can be pleasing in
a very short line -- especially when there is lively action outside
the minor set. The advantage of minimal teaching is significant when
people are tired, overheated, or feeling discouraged that there are
not more dancers. A brisk transition to music and movement gets good
endorphins flowing !
As with any suggestions, your mileage may vary. I know some people
who love to collect novelty dances -- and enjoy the
excuse/opportunity to teach unusual figures and formations. That's
not what floats my boat, but our Diversity is a Strength.
Happy Dancing !
Scott