A jam session... summing up

Jam sessions are both fun and scary. If you embrace the fact that chaos is part of the process, you'll come into it with the right mindset and you'll always learn, no matter the outcome. Also remember that luck falls on those that are prepared, so by studying the Performance Training lessons on the site you're practicing for success... or better able to recognize what went wrong if something goes bad. Lastly, the jam is for all those involved. It's okay for you to call a song and want to have it a specific way, just make sure to share the fun and musicians will be more apt to asking you to play with them in the future.

A quick side note, players that study accompaniment playing do well at jams... you're only soloing for around 15% of a song, so what you do when others are singing and soloing is very important). More info at http://www.harmonicamasterclass.com/accompaniment.htm