The boy accompanying Oscar Hammerstein II is a young Stephen Sondheim. He derides Lorenz Hart's line "weighty affairs will just have to wait", which later became a lyric in the song Comedy Tonight from Sondheim's musical A Funny Thing Happened on the Way to the Forum.
When introduced to "George Hill" aka future filmmaker George Roy Hill, Lorenz Hart advises him to focus on friendship versus love. Hill would go on to direct, among other films, Butch Cassidy (1969) and El golpe (1973), two films centered on the friendship between two protagonists.
Celebrities who are portrayed in this movie are songwriters Lorenz Hart, Richard Rodgers, Oscar Hammerstein II, writer E.B. White, future songwriter Stephen Sondheim, and future movie director George Roy Hill. This list does not include the unnamed actors of the original opening night Broadway production of Oklahoma.