Autumn Gonzales, a teacher at Scappoose High School in Oregon, faced objections over a production of “The 25th Annual Putnam County Spelling Bee,” a musical that has a character with two gay dads. She stuck with it — the show had been chosen by her students — and the production was allowed to proceed. But she is being extra cautious about next year. When her students expressed an interest in “Heathers,” which has suicide themes, she told them, “That is not going to happen.”

“I’ve always tried to go for a middle ground,” she said.

“We’re not going to do ‘Spring Awakening,’” she said, referring to the 2006 musical about young people and sexuality. “This just isn’t the community for that. But I’m also not going to deny the existence of gay people — that’s not any good for my student actors. I’m not going to be inflammatory for art’s sake, but I’m also not going to shy away from deeper messages.”

The constraints, advocates say, are having an effect on the education of future artists and audience members.

“Students deserve to have the opportunity to be exposed to a wide variety of work, not only the safest, most benign, most family-friendly material,” said Howard Sherman, the managing director of New York’s Baruch Performing Arts Center, who has been tracking the issue for years.

In some areas, the contested plays cannot even be read: In Kansas, the Lansing school board, responding to objections from a parent, barred high school students from reading “The Laramie Project,” a widely staged and taught play about the murder of Matthew Shepard, a gay student in Wyoming.

“Every year there have been a few schools that have banned a production, but this is the first time the play has been banned from being read,” said the play’s lead author, Moisés Kaufman, whose theater company offered to send its script to any Lansing student who asked. “I don’t want to be an alarmist, but it is alarming.”