[Musicians] Dance musicians - a question about 'sit ins'

Hi dance musicians :) I lamented watching some amazing conversations happening last month about open & community bands ... I'm hoping to chime-in much belatedly with Ottawa's experience. But first, I have a different question all together for the group! Way up here in Ottawa, it's hard for our local dance musicians to get much experience playing dance music with anyone other than other local musicians. Thus the question: Have any of you had local musicians 'sit in' when you've played as the hired band? This idea came up at Puttin' On The Dance 2 and we have a few keen musicians who would like to do this as part of their strategy for improving their chops. I've since talked to two touring musicians who are very open to this and think that some other bands may also be open. However, I anticipate that other bands may not be open. So, if you have experienced something like this... 1. What worked or didn't work for you? 2. How would you ideally like it structured? Off mic only or on mic depending on the person? Would you want a max number of people on stage and if so what? Would you be open to a 'sit in' at any time or only on a few designated sets? Other thoughts? 3. And how would you like to be approached by the organizers? This would definitely be a choice thing... not forced!!! I'm thinking more on how it could be thoughtfully presented and facilitated. Re sit ins... I'm talking about musicians who already have some dance experience (not random musicians). With thanks! Emily in Ottawa