So, the unit of analysis in my basic framework is an "event", defined as GD (musical), JG (musical), or nonmusical. My method can only pick up events assignable to one or several 24-hour-or-less slices of time. So, something that happened May 25 can be picked up as an event, but something that happened "in late May" cannot.
Based on the rich discussion around my Provisional List of Jerry Garcia's Sit-Ins with Other Musicians (JG-GUEST), here's how I currently think of things.
The second layer is the type of event: GD (musical), JG (musical), or nonmusical. JG is any non-GD musical event.
The third layer is sociological, and it cuts along conceptions of my own regarding what a band is (a standard personnel configuration), and those asymmetric situations in which one is either hosting others or being their guest. By "unnamed" I mean merely that this is a musical event with Garcia in which no-one can "claim" the gig.
On my readers' suggestions, in lieu of "Sit-Ins" (or JG-GUEST), I am being asked to report the entire JG category. If I could color code and that sort of thing, might be helpful.