Instead of another door, how about a rabbit hole?

… that doesn’t have a number or any expectations … kind of like the “Acid Tests”?

There are no rules, other than to explore what sounds good / interesting in the moment.

Pick the most conducive day/slot and select the participants (of those musicians alreadys scheduled and who indicate they are willing to participate) at the very “last minute” … with just enough time to insure they’ll plant their feet and equipment on stage.

http://d1oi7t5trwfj5d.cloudfront.net/48/02/86c3bc144ede9015b76d13877265/samuel-l-jackson.jpg