Pete Seeger and the blues
He hung out with Lead Belly (Huddie Ledbetter), and learned how to play the 12-string guitar from Lead Belly, and then wrote a book, How To Play The 12-String Guitar like Lead Belly.
No one would ever say Pete Seeger was a blues singer or even close. Occasionally he’d dabble in some close to blues songs on his hundreds of albums, but it being Pete Seeger, they would always end up as another folksong. Yet Pete Seeger in his own way did a lot for the blues.