Premium users can now allow free users to join private jam sessions!
Previously it was only possible to have private jams with other Premium users.
If your private jam session is open to all users or you explicitly allow your
free user friends to join, they will see the jam session in the “Connect to
server…” dialog and be able to join you.
There is a tutorial on Premium users can create private jams here:
https://forum.jammr.net/topic/1941/
Happy jamming!