In high schools across the country, there have traditionally been a set of curriculum guidelines that teachers are hesitant to disturb.

But as the population in the United States becomes more ethnically and racially diverse, re-educating teachers about how to be aware of the cultural differences in their communities has been gaining traction.

Some educators are experimenting with new approaches of teaching to motivate students and to examine concepts like racism, social justice, inequality and discrimination. These teachers are reimagining and shifting conventional curriculums to reflect their more diverse student bodies.

Mr. Emdin — who said he did not like school growing up — co-founded an initiative in 2012 with the rapper GZA to use hip-hop to teach science in 10 New York City public schools. It is about “remixing education,” he said.

Today, he advises educators on ways to incorporate these techniques into their classrooms. “Writing these raps, poems over beats, is a way of giving students’ voice,” he said.

Louis Tavares, 17, a senior at Brooklyn Prep, said hip-hop motivated him to learn. “Before hip-hop, I would go to school and not really look forward to learning,” he said. But now with hip-hop, he said, “It brings a certain type of vibe to the classroom.”

Teaching Tolerance, the education arm of the Southern Poverty Law Center, has produced social justice teaching standards that many teachers are using, from kindergarten through high school, to guide curriculum development.

“We are beginning to address race and racism explicitly in the classroom,” said Lecia Brooks, a former teacher and a member of the senior leadership team of the Southern Poverty Law Center. “We are letting go of the false notion that it is too heavy, too much for children to talk about it head on.”

The change has been gradual. One factor: Teachers are still predominantly white even as the student population grows increasingly diverse, she said. While students of color are expected to make up 56 percent of the nation’s elementary and secondary public schools by 2024, 82 percent of public schoolteachers identify as white, according to a report by the United States Department of Education.

That figure has barely changed in more than 15 years. And only 7 percent of the nation’s public schoolteachers are black.

“It is such a hard nut to crack because the education system is so steeped in bureaucracy,” Ms. Brooks said. “We have had pushback from administrators, who have seen our Teaching Tolerance materials as too radical, or too progressive.”

For Ms. Brooks, it is a sweeping shift that needs to roll out. “We believe in decolonizing the curriculum,” she said. “It can’t just be confined to language arts, or a holiday, or a month.”

Another powerhouse behind the transformation of teaching is the National Council of Teachers of English, with more than 25,000 members and subscribers worldwide. Lorena Germán, an immigrant from the Dominican Republic, is the chair of the council’s Committee Against Racism and Bias in the Teaching of English.

Ms. Germán, who came to the United States as a child, teaches at the Headwaters School in Austin, Tex. She said she experienced classroom racism as a child in Lawrence, Mass. “They wanted to bring us into a classroom that required us to dismiss our way of being in order to assimilate — as if ours had no value,” she said.

She rebelled. “I was a menace,” she said. “My chemistry teacher, for instance, would not speak to me or respond when I raised my hand.”

Today, after nearly two decades as an educator, she practices “activism every day in the classroom,” she said. “This is not about politics. This is about working toward social justice. I am constantly asking myself how I can model that thoughtfully in my classroom.”

Ms. Germán’s ninth-grade students, for example, study graffiti and debate questions such as: Is it vandalism? Where does it come from? What does it mean? What does it contribute to society? Does it count as text? Is there a message there?

The students read Gene Luen Yang’s “American Born Chinese,” a graphic novel that centers on issues of conformity, issues of identity, particularly around race, she explained. “The discussions get pretty heavy.”

“My students are really engaged with the content,” Ms. Germán said. “Over and over, they comment on how modern it is. What they are saying is that it’s very relevant to their lives.”

In 2018, she co-founded #DisruptTexts to help “teachers build a community and find alternatives to the white male-dominated literary canon,” she said.

Tricia Ebarvia, whose parents immigrated from the Philippines, also helped found #DisruptTexts. She teaches AP English Language and Literature at Conestoga High School, outside Philadelphia. “Part of the work I have been doing is grounded in a deep belief in public education as being a transformative tool for social justice and for democracy,” she said. “That’s why I went into teaching.”

As an Asian-American, Ms. Ebarvia was “socialized in a white culture,” she said. “Through all of my K-through-12 education, I never read a text that addressed my racial identity. I internalized that, to be considered well read, I needed to read Shakespeare and Tolstoy and Nathaniel Hawthorne — all the traditional greats. So initially, I taught those kinds of texts.”

“But I have worked against that in my classroom over the years,” she said. “For example, my 10th-grade class is reading ‘1984’ by George Orwell as part of our required curriculum. My goal, though, is to study truth. What does Orwell, this white British man, have to say about truth, what is the perspective he is coming from with people in power trying to oppress others?”

Students understand there are big problems in the world. “They want to be able to have an informed conversation,” Ms. Ebarvia said. “School is a place we can have these conversations and establish a habit of seeking multiple perspectives.”

The cultural classroom change is happening, but it is far from mainstream. Ms. Ebarvia said that there could be pushback among teachers but that was also encouraged by the growing number of those willing to engage in conversations about how to educate a new diverse generation.

To re-educate herself, Ms. Ebarvia is continually looking at racism in her own life. “To teach, I must do that self-reflection, and that’s hard work,” she said.

BY KERRY HANNON