"Oh, What a Beautiful Mornin'" is the opening song from the musical Oklahoma! written by composer Richard Rodgers and lyricist/librettist Oscar Hammerstein II. It is sung by Curly McLain at the beginning of the first scene and was the first a cappella opening to a musical.
"Oh, What a Beautiful Mornin" was covered and renamed "Oh What a Beautiful Morning" as a single by Jan & Dean in 1987. This cover was a post accident from lead singer Jan Berry near Dead Man's Curve in California.