Who are "you people?" Are they on Mudcat? Do you know this? How?
If this is not at the clubs or pubs you go to, how do you know it happens?
What did you want to play? The same type of music they did, or were you going to "show them what real music sounds like?" (A man came to our folk music jam, and announced, "I *hate* folk music!! I'm going to show you-all what GOOD music sounds like!" Needless to say, folks didn't exactly roll out the red carpet!) Did you want to sing at an instrumental jam? Play an instrumental tune at a song jam?
Are you sure it was a jam you wanted to join, and not a show or a rehearsal? (We've had people walk right up and join in when we've been at a paid performance--art fairs, "heritage festivals," and the like, where they pay you to set up in an area and play for 3 hours or so for folks passing by. Needless to say, we didn't appreciate the 'help!')
I'm not accusing you of anything wrong--I just want to point out that there are way too many "unknowns" here for anybody to give you any good suggestions.
Why don't you slip in a few details, and see if we can come up with anything solid?
Denise:^)