Gramps has been a fixture busking and small-venue concertizing in Seattle and around the Pacific Northwest for decades. I like your very apt 'cross between Tuvan and Popeye' descriptive of his voice, and I think he would too. Gramps also loves palindromes, of which I bet he did some at the concert you saw. He is, as you say, a wonderful entertainer and pretty good National picker too. He's also done some wonderful stuff occasionally with Bainbridge Island brass player Jas Linford as well. Tuba and dobro. Yeah!
Carter