When English folklorist Cecil Sharp (not "Cecile") collected songs in the Appalachians (1916–1918), he found hundreds of ballads and folk songs with clear British Isles origins—preserved orally for generations in isolated mountain communities.
Sharp called them "folk-songs" or "traditional songs." The definition:
Songs transmitted orally, of unknown authorship, existing in multiple variants, shaped by community aesthetics over time — distinct from composed, printed, or commercial music.
English Folk Songs from the Southern Appalachians (1917, 1932 with Maud Karpeles) — 1,600+ tunes. Founded the English Folk Dance and Song Society (EFDSS). Inspired the US folk revival (Seeger, Lomax, Dylan).
Sharp didn't "find foreign songs." He found British songs that became American through oral transmission — the definition of tradition.