Fiddle; photo by Steven Higgins on Flickr (noncommercial use permitted with attribution / no derivative works).
Official State Musical Instrument of Oklahoma
Oklahoma designated the fiddle (violin) as the official state musical instrument in 1984 as a symbol of the exceptional musical heritage of the state. Oklahoma also recognizes the drum as a music symbol (the state percussive instrument). All State Dances & Music Symbols
According to PBS.org, the fiddle is the oldest instrument of American roots music and was virtually the only instrument found on the frontier for many years. There are written accounts of fiddle contests as early as 1736.