Ditto--what subgenre?

Country: Carter Family, Delmore Brothers, Bascom Lamar Lunsford

Cajun, Zydeco, Cajun Swing: Clifton Chenier, Lost Bayou Ramblers/Les Freres Michot, Hackberry Ramblers, Red Stick Ramblers, Joseph Falcon

Old Time: Original Red Clay Ramblers, Tom Ashley, Tommy Jarrell, Dave Landreth/Allen Street String Band, High Woods String Band, Dock Boggs, Buell Kazee, Olabelle Reed, Dwight Lamb, check out the Missouri Traditional Fiddle & Dance Network for some fun stuff (sorry, old-time is my pet genre).

Appalachian, Bluegrass: Jean Ritchie, Phyllis Boyens, Hazel Dickens

Blues: Robert Johnson, Sonny Terry & Brownie McGhee, Son House, Mance Lipscomb, Elizabeth Cotten, Etta Baker