Well folks I haven't experienced a session before but it doesn't sound like something I'd want to get involved with either. The feelings here seem fairly strong about what a session is but no one has made that definition very plain as Mike was trying to point out. From what I've gathered after reading these posts a session is:

A group of people who perform together certain specific types, styles or kinds of music, right down to the type of chords used in any given secified form. These folks do not necessarily comprise what might be considered a "band" but rather a loose conglomeration. These groups do not jam but rather might be considered a preservation society for a given type of music. The type of music which is played and the instruments allowed at the session are determined by someone who is either hosting or leading the session. These events happen in either an open or invitational format and can be in a public place or not. Those performers in attendance are obviously lovers of specific disciplines or styles or just lovers of the whole idea of music and performance and can be professionals or amateurs. Alcohol can be but is not necessarily a component in these events. Does that about cover it?

So if I were a lover of say jug band music, I shouldn't expect to be able to carry my washboard into an Irish session and find acceptance by those in attendance for the type of rhythms I might be able to produce because the washboard is not the type of percussion instrument normally associated with Irish music. Unless of course the rules dictated by those governing the session allowed such diversity and my abilities were deemed adequate by the group.

Wow, that's a lot of hoops to have to jump through just to have some fun playing music with others. I find it hard to believe that all these forms, stlyes or genres that so many hold as sacred today ever started out with that intention. I think it was just a bunch of folks who were having a get together to enjoy some good food, drink and music. I'm not saying there weren't those with specific ideas that they wished to explore. I mean there were certainly those, years ago, who could not handle the idea of Elvis. Heck, Elvis couldn't handle The Beatles. That didn't stop the metamorphose of music from changing exapanding and growing into new and different expressions and so it continues despite the best efforts of some to confine it to a static identity. It is only ever dynamic, changing with each new soul who is enticed by the calling to explore it's endless reaches. It is as well a glorious gift well worth sharing with others whether they be novice or sage.

End of rant-