ASHLAND, ORE. — The idea came to Bill Rauch in the early 1990s: What if he directed a production of Rodgers and Hammerstein’s “Oklahoma!” where the lovers were same-sex couples?

A gay man in a committed relationship at a time when marriage equality seemed like an impossible dream, he was sure that it would be revelatory. He was equally certain that he would never get the rights to stage the musical that way. For more than 20 years, he did not dare to ask.

But on an August afternoon two summers ago at Oregon Shakespeare Festival, where he is the artistic director, Mr. Rauch watched a version of his vision unfold. Onstage, in costume behind music stands, actors gave a public reading of the show — an “Oklahoma!” where Curly and Laurey, the central couple, were women, and the secondary romance was between two men, Will Parker and Ado Andy (changed from the original Ado Annie).

In the audience, seated close to Mr. Rauch, was Ted Chapin, the vigilant longtime overseer of the Rodgers and Hammerstein catalog, who’d listened to Mr. Rauch’s nervous pitch and given a cautious go-ahead.