Shannon Rider as Tammy Wynette

The Heritage Music Theatre seems to be onto a good thing with its song-laden stage plays about county music stars and other folk heroes.

Director Elizabeth Craven’s first effort in this category, “Always … Patsy Cline” sold out three local runs, and went on to play the Wells Fargo Center and the Uptown Theatre in Napa.

Craven followed up with “Hank Williams: Lost Highway,” and last year she formed the Heritage Musical Theatre to stage “Woody Guthrie’s American Song,” which opened in December for a month-long, sold-out run at the Cinnabar.

Now the current Heritage show, “Stand by Your Man: The Tammy Wynette Story,” has sold out its run at Petaluma’s Cinnabar Theater and will be extended. It was originally scheduled to close Sunday, April 10.

New performances have been added at 8 p.m. Saturday and Sunday, April 15-16. (An additional matinee at 2 p.m. Sunday, April 17, already has sold out.)

Admission: $25-$35. Information: (707) 763-8920, www.cinnabartheater.org.