Oklahoma wheat bending in the storm; photo by George Thomas on Flickr (noncommercial use permitted with attribution / no derivative works).
Official State Song & Anthem of Oklahoma
"Oklahoma!" (music by Richard Rogers, lyrics by Oscar Hammerstein II) was adopted as the state song and anthem of Oklahoma in 1953. This "fresh new tune from a musical and a movie of the same name" replaced Oklahoma's original state song ("Oklahoma, A Toast," adopted in 1935) because it was considered by many to be "too slow and too much like a funeral dirge" (quotes from Oklahoma Historical Society). All Oklahoma Songs - All State Songs
Oscar Hammerstein; "Songwriters write songs for people to sing and nothing makes them happier than to know that their song is being sung. Mr. Rodgers and I are very proud that our song has been adopted by your State. Play it and sing it loud and long and often!"