Just as Bartok’s recordings of Hungarian and Romanian folk songs influenced his later compositions, a particular recording of an old cowboy tune had an impact on the “Hoedown” movement of Copland’s Rodeo.  Listen to this NPR story on that tune and its transformation from a western march to an orchestral dance.  To see what other folk tunes appear in “Hoedown” read the paragraph on that movement from the Wikipedia article on Rodeo.  The link will take you directly to that paragraph.