For some reason, this thread seems to concentrate on Irish sessions as the model for a jam session. IT ain't necessarily so. Irish get-togethers have their own rules, which seem to be focused on everyone playing melody in unison as fast as possible, with the exception of bodhran players who are doing something else.The jam sessions I think of are those that involve string-band music, blues and any other form of music in which improvisation is an important part. And for these types of music, a so-called "elite" session can be a real bit of advanced education for musicians who can handle it. Sure, there's a place for open jams; slow jams and even (I guess) for breakneck velocity jams, but a jam that puts a group of competent musicians together in a setting where it's possible to listen to what the others are doing is a neglected form of get-together that can produce some fine music.