“Black Mountain Rag” was composed in the 1930s by fiddler Leslie Keith, who built it from an earlier tune called “The Lost Child.” The piece spread through the country and bluegrass scene of the 1940s as other fiddlers picked it up from radio broadcasts of Keith’s playing. Curly Fox had a hit with the tune in the 1940s, and Tommy Magness adopted it into his repertoire and became one of the players most strongly associated with it.
The Roy Acuff connection traces to January 1949, when Acuff and his Smoky Mountain Boys recorded a session of fiddle tunes featuring Tommy Magness. The session yielded eight tunes — “Grey Eagle,” “Dance Around Molly,” “Black Mountain Rag,” “Pretty Little Widow,” “Smoky Mountain Rag,” “Lonesome Indian,” and “Bully of the Town” — with Magness’s fiddle at the center. The Acuff “Black Mountain Rag” recording carried the tune to a wider commercial country-music audience.
The tune crossed into bluegrass through subsequent treatments and became a flatpicked guitar showpiece largely through Doc Watson, whose recordings set the canonical guitar arrangement. On recordings the piece has been variously credited to Magness, to Keith, or simply listed as traditional; most contemporary attributions correctly point back to Leslie Keith’s 1930s composition.