Fiddle virtuoso Vassar Clements, who died Tuesday at 77, was a bluegrass star and beloved session player, perhaps best known for his work with the Nitty Gritty Dirt Band, but he could play with anyone from any genre — Paul McCartney, the Grateful Dead, the Byrds, Woody Herman — leading to appearances on more than 2,000 albums. All without ever having learned to read music. Plus, Kris Kristofferson called him ”the nicest person I ever met in the music business.”