On my first visit to the LOC, I met Joe Hickerson, now Head Emeritus of the Archive of Folk Culture, American Folklife Center of the Library of Congress. Here’s a recent note from him.
“I do remember building up a vertical subject file on bones [probably where our newsletters are stored], but not a bibliography. I remember becoming a friend of Percy Danforth in Ann Arbor when he did a guest set at a concert I did in 1969(?) at The Ark. He subsequently was recorded by the Folk Archive at the Library and gave workshops at folk festivals, etc. I was fascinated by the fact that, as a boy, he learned to play the bones from an African American youth in Washington, DC.
I also remember the visit(s?) of Eric Ilott to DC under the aegis of folks (esp. Jonathan Eberhart) in the Folklore Society of Greater Washington. I believe he used four bones in each hand. All best. Joe Hickerson