Melissa Tempel's first grade class at Heyer Elementary School in Waukesha County, Wisconsin, has spent weeks preparing for its upcoming spring concert.

Tempel and her co-teacher, dual-language instructors at the school, wanted the concert to have a theme of world unity and peace. Among the songs they selected: "It's a Small World," sung in Spanish, and "Here Comes the Sun" by The Beatles.

Students were also set to perform "Rainbowland," a 2017 duet by Miley Cyrus and her godmother, Dolly Parton, with lyrics that advocate for inclusion. Tempel started rehearsing with her students as soon as the song was suggested by another faculty member and approved by Tempel and her co-teacher. Her first graders, she said, need as much time as they can get to learn the songs by heart ahead of the concert, just before Mother's Day.

"My students loved it immediately," Tempel told CNN of her classroom's reaction to "Rainbowland."

But within one day of students learning the song, Tempel said that school administration asked her to remove "Rainbowland" from the concert. In a statement, the district said it called for the song to be removed because its lyrics "could be deemed controversial" according to a school board policy on controversial issues in the classroom.

"Wouldn't it be nice to live in paradise, where we're free to be exactly who we are," Cyrus and Parton sing. "Living in a Rainbowland, where you and I go hand in hand. Oh, I'd be lying if I said this was fine, all the hurt and the hate going on here."

Representatives for Cyrus and Parton did not immediately respond to CNN's request for comment.

"It's really about if we could love one another a little better or be a little kinder, be a little sweeter, we could live in rainbow land," Parton said of the song in 2017, while Cyrus separately noted that some of the lyrics nod to "different races and genders and religions."

"(It would be great) if we all did come together to create and said, 'Hey, we're different, that's awesome, let's not change to be the same, let's stay different but let's come together anyway.' Because a rainbow's not a rainbow without all the different colours," Cyrus told NME.

Tempel said that "Rainbowland" isn't "just a song."

"We're trying to support inclusivity," she said. "The love and acceptance piece, and being who you are, I don't think there's anything political about that."

Per the Waukesha school district's policy, a "controversial issue" is one that "may be the subject of intense public argument" or may have "political, social or personal impacts and/or the community," among other criteria. When reached by CNN, Waukesha school district Superintendent James Sebert did not specify why "Rainbowland" was deemed controversial.

School districts across the U.S. remove rainbow imagery

Tempel, who is worried the ban of "Rainbowland" is tied to broader efforts to curb discussion of LGBTQ2S+ topics in classrooms, said school district officials have tried to remove other references to rainbows in schools. She said that last year, administrators asked teachers throughout the district to take down rainbow decor and to stop wearing rainbow lanyards or clothing.

Sebert said some signage has been taken down in accordance with the policy that resulted in the "Rainbowland" ban, but did not specifically refer to signage with rainbows. He told CNN that the district has its own "Commitment to All" poster in both English and Spanish to reinforce that students are "respected," "belong" and "have a voice."

The Waukesha County school board was more explicit with its guidance on LGBTQ2S+ students, earlier this year approving a resolution that encourages teachers to avoid using a student's preferred nickname or pronouns unless they've received written approval from the student's parent.

School districts across the US are increasingly limiting faculty's ability to discuss LGBTQ2S+ topics with their students across grade levels. In Florida, a law dubbed "Don't Say Gay" by its opponents, banned teachers from discussing sexuality and gender identity with students in kindergarten through third grade.

Earlier this year, USA Today reported that school districts in Delaware, Ohio and Wisconsin, among others, have banned faculty from displaying Pride flags. And school districts in states including Texas, Louisiana and Michigan have faced bans on books that include LGBTQ2S+ characters or topics.

In Kettle Moraine School District, also in Wisconsin, teachers have been banned from displaying Pride flags or using pronouns in their email signatures, when school district officials reinterpreted an old policy that bans "partisan politics, sectarian religious views, or selfish propaganda," CNN reported last year.

After the ban on "Rainbowland" at Heyer Elementary, another faculty member suggested Tempel and her co-teacher replace the song with "Rainbow Connection," Kermit the Frog's famous anthem about hope and trying to achieve one's dreams. But that song was initially banned, too, until parent members of the Alliance for Education in Waukesha addressed the ban with school staff, and administrators eventually reversed the ban, Tempel said.

The concert will go on as planned, with students singing "Rainbow Connection" instead of "Rainbowland," a result that is "fully supported by the Superintendent," per the school district statement Sebert shared with CNN.

Tempel and teachers remain committed to inclusion

Samantha Siebenaller, a parent whose child is in Tempel's co-teacher's class, praised Heyer Elementary faculty for "their dedication to creating an environment where inclusion thrives in spite of the Board."

Siebenaller said in a statement that some Waukesha School Board members have "embarrassed our community ... with their lack of commitment to diversity, equity, inclusion and belonging."

CNN has reached out to Waukesha School Board President Kelly Piacsek for comment.

Tempel, for her part, hasn't removed the rainbows from her classroom. Her students were disappointed when they learned they would no longer sing "Rainbowland," but she remains committed to showing her support for inclusion in different ways. She spoke up about the song ban on Twitter, drawing thousands of eyes to her school and its upcoming concert.

She told CNN that what's most important to her is being there for the children she teaches -- "making sure my students feel safe and supported at school, and that their identities are appreciated, no matter how they identify."