How a Jam works:
Get a number of musicians together, assorted instruments. Usually in a jam, not performing situation, you would form an inward facing circle. Someone picks a song, and kicks it off. The person picking will lead it. The verse is played, and breaks or solos are essentially passed around. Guitar player playes a verse, does some improv based on chord structure and harnmony, then it goes back to the group and singing. This goes around till everyone that wannts a piece of it gets a shot at it.
In a performance jam, it usually works about the same, but we might not drag a song out as long, and we would not be in a circle. More stretched out across the front.
I do enjoy the dulcimer and the jam haas been established as a come one come all, so I wouldn't do anything to attempt to change it. I just get a little frustrated during their songs. Thei portion becomes more of a recital, then back to jamming.