I'm not sure if this counts as folk art per say, but what in the case of pervasive RPGs? For instance, an RPG that isn't really a LARP but isn't really a tabletop RPG either. Here's an example from a game I'm about to run called, "Holy Shit, It's A Spy!?" The idea is that booklets that teach you how to play and give you a character sheet are distributed throughout a college campus. Anyone who picks one up can start playing, and engages with other people on campus (random strangers usually) in secret meetings, using diceless moves on each other, similar to Apocalypse World. What that creates is this individualized player experience, the potentiality for a larger group to experience a game , while condensing the microcosm to 2-4 players holding a secret meeting at a time. The system is general enough in description and mechanics to allow for people to create their own idealized spy world (since I'm playing with archetypes).
AW is so great because it allows individual groups to make with it what they will. In some senses it is like a kit you can use to build this apocalyptic world, to build these experiences, and, similar to the sound and participation style in a drum circle, every group running it will have a unique culture that emerges from play. What happens in terms of mass participation and craft sharing is entirely dependent on the inclusiveness of these small groups. I completely agree with Megeuy's point of the impossibility of a regulated collective.
So what I'm hoping happens with this spy game is that people will just take these general concepts in the game manual and devise their own ways of playing, their own stories. AW is akin to sandbox play in terms of the potentiality for infinite expansion and exploration based on player/MC creativity. Vincent Baker called his game, "Apocalypse WORLD," not, "Mad Max." Can AW be Mad Max? Absolutely. It can also be anything else, but it encourages you to veer slightly toward mad max. From a design perspective, a game maker should consider that her game will be played by people in groups of 2-5, and that that group will devise its own culture and your game will cease to be your game. There are lots of players who pick up systems simply to facilitate their own settings and narrative they wish to build. The system is just there as a sort of crude paint brush in most cases, but with AW it can be a highly masterful set of paintbrushes designed to help you (the folk artist I guess we could make the argument for) paint the desired world.