Re: Define Touch Head, please.
In addition to the explanation above: the term came around when the over-produced In the Dark came out and Touch of Grey* became popular among the masses, as close to top-40 as the Dead ever came, and it brought in a wave of new, well, not fans but people coming to the shows for the first time and seeing the scene as a safe place to act the fool. Like an 18 year old who never drank before being dropped into a college fraternity.
Now it's been a few years so the term is applied loosely not just to those of that specific age (who have either outgrown acting like idiots or gone back to Jimmy Buffet and Garth Brooks) but any disruptive newcomers. The are closely akin to wooks and bros, in that regard. The don't bother to learn the music and don't know much beyond that album, Casey Jones and Truckin'.
*AKA in the dark heads