With some careful planning with the band to make sure the tune/key changes worked you could segue from one dance/tune combo to another and it could be a really fun challenge for the dancers.

Agreed with whoever-it-was that you'd need to keep the dance figures within a fairly narrow range of complexity, but that leaves you with a LOT of dances and tunes to work with.  I absolutely would not spring this on a group including new beginners, but dancers who are comfortable with no-walk-through dances should be able to handle it just fine.

With the right band, the right choice and order of dances, the right prep for band, caller, and dancers, and a group of willing dancers who know in advance that this is what they signed on for - sure, why not. I wouldn't do it at a regular dance party, it would be something for a workshop or session at a dance festival, where those who didn't like the idea could avoid or choose something else.

The dances could be familiar or not. And yes, straightforward with figures that will be familiar to (most of) those who are there. It can help if each dance starts approximately the same way, so you have a moment to adjust to the new tune/time signature. The band has to be able to make a clear indication of any rhythm changes as one dance ends and the other begins.

Brooke Friendly