"Oh, What a Beautiful Mornin'" is the opening song from the 1943 Rodgers and Hammerstein musical Oklahoma!
It is performed by the character Curly McLain, and is arguably the most endearing song from the show. It has long become a standard, and the title speaks for itself. In the 1955 film version it is performed by the cowboy riding out on this beautiful morning on his grey horse.
Alexander Baron - London, England