I think its very possible that this is a genre that's played out. When Art started it he could have had total bunk artists lines up as guests (not saying that he did) and without the internet at our fingertips we had no way to know. There was an innocence. The ground was fertile. Art was totally at the right place at the right time. Because those that have tried to tap into his magic have totally blown it. Well, not totally.
There are those out there I'd still like to hear but finding them and where they're at is a challenge.