Many of the various anthologies and various artists collections are great ways to start a collection, but I want to offer a list of essential performers who ought ought to form the core of an American traditional folk music collection. I don't know what's currently in print, so I'm not naming specific LPs or CDs.

I'm not ignoring music from other places, but that's another list.

I'm also leaving out a lot of singer-songwriters. Again, that's another list, as is the list of essential blues singers.

Just for starters:

(in more-or-les alphabetical order; NOT order of importance)

Joan Baez
The Beers Family
Hank Bradley
Guy Carawan
The Carter Family
Paul Clayton
Judy Collins   (early albums)
Elizabeth Cotten
Jimmie Driftwood
Rambling Jack Elliott
Bob Gibson
The Golden Ring (The first Folk-Legacy album)
Woody Guthrie
Larry Hanks
Sam Hinton
The Holy Modal Rounders
Mississippi John Hurt
Cisco Houston
The New Lost City Ramblers
Obray Ramsey
Jean Ritchie
Jimmie Rodgers
Mike Seeger
Peggy Seeger
Pete Seeger
Kilby Snow
Happy Traum
Dave Van Ronk
Frank Warner
Doc Watson
Hedy West

I would also include the Harry Smith Folkways Anthology, the live recordings from the Newport, Philadelphia, Fox Hollow and San Diego Folk Festivals, the Lomax Southern Journey series, and a collection of Freedom Songs such as the Smithsonian "Voices of the Civil Rights Movement" set.