Well said by AJ above….Zydeco, Creole, Cajun are three different sounds and after a few years of playing you should be able to pick them out…….just to add a bit…i love to play zydeco and some of it by itself sounds terrible because it is too simple and repetitive….the grove of the band gives most of the feel and sound ….by adding just a bass guitar and drums will make a world of difference….the key will not make a world of difference but an internal mic will…i have one in both a Bb and C...…..Keith Frank, Chris Ardoin, J Paul, Geno Delafose, Brian Jack, Wayne Singleton….all of these guys have several songs on a C box
I love B-flat. I have been performing Zydeco continuously since 1998. Up until 2 years ago, I didn't even own a C accordion, much less perform on one. I have one now, and I switch between the C and the B-flat.
I have never attended a jam session, and not sure that I ever would. I don't think it is a valid concern that you MUST have a C accordion or you can't play at a jam session. If there's more than one key at a jam, take turns.
Get the key you want.
Having said all that...
A month or so ago, we hosted Jeffery Broussard - Mr. Oh B-Flat himself. Guess what - he was playing a C accordion all night! I kinda teased him about that.
BTW, an unexpected treat of the night was the fact that D'Jalma Garnier was playing bass. I knew of him as reviving the Creole fiddle style, but I did not know about his rock roots playing bass. For me, as a former blues/rock bass player turned Zydeco accordion player, it was a fascinating discussion we had about some similarities in our musical journeys.