This is an article reprinted from the 2011 Jazzidiot Blogspot. Possibly still relevant?
I have been thinking about the nature of Jam Sessions. In New York, jams are dominated by professionals, as perhaps they should be. In London, apparently, there is a jam every night of the week, mainly for professionals, but with amateur sit ins; some with a cover charge for the audience and musos in for free; others where they pass a bucket round and everyone tosses in a coin. Here in Melbourne, deep south capital of culture (not), jam sessions seem to come and go, and vary between the deadly serious rendition of (normally) bebop, and the entirely light hearted mangling of whatever tune springs to mind. No prizes for guessing where the Melbourne Jazz Jammers sit.
We have no jam sessions for professionals, for the simple reason that those few professionals that survive on Melbourne gigs are way too busy trying to earn a living and/or claw their way to the top. It shouldn't take long, as the top is remarkably close to the bottom.
It is a pity really, as jam sessions, free or not, are an easy entry point for people interested in listening to, or playing, jazz. I feel that they really help promote the jazz scene, and build an audience for up and coming musos.
The MJJ sessions are squarely aimed at the enthusiastic amateur. This invites disaster as there are always a few whose self esteem runs way ahead of their ability(*) . But in between the train wrecks, are moments of ballad mangling delight - a bunch of incompetents having fun is always entertaining, and the Jammers often have the audience numbers to prove it.