Interesting question...
From my experience: I have been to contra dance across New England and
Mid-Atlantic areas and have never seen a special container for "tips".
I my general understanding is the admission of the contra dance pays for
the band, and usually the band is paid a guarantee and a percentage of
the door or just a percentage of the door (depending on the specific
contra dance). Some contra dances have a specific formula to calculate
what the band is going to be paid...
As a caller and dancer, I would frown upon a special container for "tips".
Respectfully Submitted,
Jeff Petrovitch