Island Pond, Vermont had a group who would do that 30 years ago going to Dead Shows.
they had a 'communial' living but it wasn't really. It was a heirarchy of leaders and people who were second teer dupes.
It was well known. Most people would stay away from them. They would have a dance circle with all of them. They would only mingle while being watched, and if you started to 'unhypnotize' them (for example the girl was saying how she of course would help care for othter people's kids for free and I asked about why she had to and what were they doing for her and which point the 'handler ' (I will call her that) came over and pulled her away.
It seemed to be a cult. They would tour the shows. But they weren't considered by other Deadheads to be 'cult' and they were not part of the band.
Nor did I ever see them or hear of them going to Bread-n-Puppet, which many Grateful Dead fans would go to (in the Summer) for their 'bread and puppet' camp-out (it was a two day thing, public welcome).
Nor would you ever see them out anywhere else. I've never been to Island Pond. It's almost in Quebec.