Natural light streams in from a glass atrium where students are invited to lunch at Cardozo Education Campus in Washington, D.C., on Thursday, Aug. 27, 2015. Cardozo Education Campus will offer 22 electives this year, up from six last year. (Nikki Kahn/The Washington Post)

Principal Tanya Roane heard something that made her stop in her tracks during the first week of school at the District’s Cardozo Education Campus. It was the sound of singing.

More than a dozen teenagers with their heads buried in sheet music were offering their rendition of Adele’s “Rolling in the Deep” in a new choir class at the Columbia Heights school.

To Roane, it was the sound of high school.

“You had choir in high school. I had choir in high school. We didn’t have this at Cardozo,” she said. “I think I’m going to cry.”

Low enrollment and an intense focus on remediation have yielded a bare-bones curriculum at many schools in the District. Last year at Cardozo, students had about six elective courses to choose from in addition to the Junior Reserve Officers’ Training Corps program (JROTC). The campus now plans to offer 22 electives, introducing courses in ceramics and debate, among others, and bringing back such high school staples as marching band and choir.

Ning Zhou teaches Chinese I to students at Cardozo Education Campus in Washington, D.C., on Thursday, Aug. 27, 2015. Chinese is one of the 22 electives offered to students at Cardozo this year, up from six last year. (Nikki Kahn/The Washington Post)

D.C. Schools Chancellor Kaya Henderson has dubbed the 2015-2016 school year “The Year of the High School” after she put extra funds toward boosting offerings in middle schools and elementary schools the past two years, efforts at making the curriculum more equitable across the city. The new courses at Cardozo come from $13 million dedicated to giving students more options at the city’s high schools.

Henderson said she hopes the investments will improve students’ satisfaction and attendance and help the traditional schools attract more students in a city where families have an increasing number of public schools to choose among, including the city’s many charters.

Course offerings have long varied dramatically across the District. Wilson, the city’s largest high school, in upper Northwest, offered 27 electives last year, including photography and public speaking. It also offered 29 Advanced Placement courses, ranging from Latin to microeconomics. In a low-income neighborhood across town, Anacostia High had four elective courses, in addition to JROTC, and three AP courses.

Every neighborhood school is expected to offer at least 20 electives and six Advanced Placement courses this year. The District also is funding athletic directors at every school to broaden sports and fitness offerings, and city schools are expanding career and technical programs.

Coolidge High, which has 400 students, offered just six electives last year. Yearbook, a high school tradition, was an after-school activity, and the finished product was available only online. This year, Coolidge will offer 19 electives, including public speaking, journalism and a yearbook class.

Not every high school will see changes: Wilson has not added any new courses, and application and alternative high schools did not get similar boosts for their programs.

Just a week into the school year, schools are adjusting to the new schedules and the impacts of new staffing and courses.

Roosevelt High School added about 10 new teachers and a slew of new classes, but it’s still operating in a cramped swing space because the reopening of its modernized high school has been delayed until next fall. Many teachers are sharing classrooms, a concern that came up at a recent neighborhood meeting.

Ballou High School in Ward 8 is undergoing a “reconstitution” designed to radically shift the school culture and improve academic performance. Principal Yetunde Reeves said she is trying to build in the new elective courses while keeping up with enrollment growth and improving the school’s academic bottom line when “most of the school is below grade level.”

To make time for the new electives and “deep interventions” for students in reading and math, she created an extra “skinny period” by shaving 10 minutes from other classes throughout the day, she said.

The investments in high school courses come on the heels of major investments in facilities that created high schools that, in many cases, are architectural showcases with state-of-the-art amenities but minimal course offerings.

Woodson High School reopened in 2011 with a $102 million facility, including classrooms and laboratories loaded with equipment for a science and technology focus, but it lacked full funding for a corresponding program.

“I was so excited when this new school opened. I said: ‘Wow, it’s a great building. It looks good. The classrooms are state of the art,’ ” D.C. Council member Yvette M. Alexander (D-Ward 7) said at a recent news event at Woodson. “But I was concerned about the programs inside the school.”

Alexander said she is heartened to see new investments in courses. The school started a STEM (science, technology, engineering and math) academy last year, and Henderson announced that two new career academies focused on engineering and information technology will open at Woodson next year.

Cardozo reopened after a $130 million renovation in 2013 — the painstakingly restored building has sunlight streaming into classrooms and sweeping views of the Washington Monument and the U.S. Capitol. It has a swimming pool and stocked computer labs.

But its enrollment was well below the building’s capacity, even with the introduction of middle grades. The school went through a reconstitution, which called for an overhaul of the staff and an intense focus on improving reading and math results. That meant hard decisions for Roane during the next two years. Choir and band got cut.

Acoustically engineered music rooms were used for math classes, and the swimming pool went untouched for two years, without funding for a pool operator.

“People checked the chlorine, but not even a toenail — nothing — has gone in that pool,” Roane said.

The principal hired a pool operator this year, and the school can offer swimming classes with the addition of a new physical education teacher.

A new band director was hired to rebuild a music program. He plans to create jazz, concert and marching bands.

During the first week of school, 10th-graders in a new computer science class were being introduced to a robotic ball, called Sphero, that they will learn to program. In a Mandarin class, students giggled while they practiced saying, “Ni Hao” (Hello) and “Xie Xie” (Thank you) with their new Chinese-language teacher.

Gabriel Solomon, 17, a senior, said he was surprised to see Chinese on the list when he registered for classes, and he signed up.

“Nowadays, everyone is speaking Spanish,” he said. Last year, his only elective was JROTC. This year, he signed up for an acting class. “It gives you a way to express yourself,” he said.

Roane said that having extra courses that students care about will give them an important outlet and could help with discipline problems. As she watched the teens during choir practice, some were belting out the song and dancing along or making each other laugh.

“Look at them,” she said. “They are enjoying themselves.”