CAMBRIDGE -- Caleb Casiano waited a long time to sing in the renowned choir at St. Paul's Choir School. Now in the fifth grade -- his third year at the school, and his first year in the choir -- he is carrying on the school's musical and academic tradition, like his brother before him.

St. Paul's Choir School (SPCS) is the only private Catholic all-boys choir school in the U.S. Having added two younger grade levels in recent years, the school now offers grades three through eight, and students can join the choir in the fifth grade.

The Casianos live in Roslindale and attend Mass at St. Paul's Parish in Cambridge, the parish to which SPCS belongs. As a small child, Caleb watched and waved as his older brother Christian performed with the choir in the school's annual concerts.

Patrick Moran, the school's director of admissions, remembers seeing Caleb with his parents at every concert Christian sang in. The other students at the time also got to know Caleb from being around so often.

"He was always pretty wide-eyed at the concerts," Moran said in a Feb. 8 interview.

Christian attended the school from 2012 through 2017. He then went on to St. Sebastian School in Needham and is now studying music and chemistry at Fordham University. Two years after he graduated from SPCS, Caleb was able to enroll.

The school has a tradition of inviting the incoming class to the eighth-grade graduation. The outgoing students shake the hands of the incoming students, a living sign of what they may someday become.

Moran said that when Caleb, as a newly enrolled student, attended the ceremony and shook the graduates' hands, it was like he was "receiving the mantle."

"That's how he's always looked at the school, as someplace that he wanted to be," Moran said.

Caleb started the third grade at SPCS in 2019. That year, the third- and fourth-grade students sang part of "Silent Night" with the choristers in the annual Christmas concert. The following year's concert was held virtually due to the coronavirus pandemic.

Finally, upon entering fifth grade in the fall of 2021, Caleb was invested as a chorister himself.

"I'm really happy that I get the opportunity to follow in (Christian's) footsteps," Caleb said, speaking to The Pilot on Feb. 11.

The school's various academic subjects tie in with the choristers' musical training. They study French, Latin, piano, music theory, and the Scriptures, all of which help them better understand the musical texts they work with.

Lucy Casiano, the boys' mother, said she thinks the students at SPCS benefit from being in small classes of all boys. According to the school's website, the average class size is seven students.

"Having that one-on-one with the teachers, in a small (classroom) setting, is great," Lucy Casiano said.

Moran teaches social studies at SPCS and has had both of the Casiano brothers as students. He noted that they are one of the only families that have been connected with the school from the time he began working there almost a decade ago.

"They're just a remarkable, faithful family with two really good boys," he said.

He recalled Christian's discipline as a student while he was at St. Paul's. One memorable example of this was when Christian's eighth-grade class went on a trip to Washington, D.C. Almost every day of the trip was a dress-down day for the students, but Christian consistently dressed up with a button-down shirt, khakis, and a tie. Instead of carrying a backpack like most of his peers, he carried a briefcase. Moran observed that, except for his young age, Christian looked like he belonged in the capital, as though he worked there or was visiting on business.

Moran said Caleb's "defining trait" is his curiosity. During the afterschool program, while his peers usually play video games, Caleb will use the time to watch documentaries on his Chromebook.

The boys' father, Bert Casiano, said their experience at the school has been "extremely positive."

"My older son benefited from the education he got at St. Paul's that led him to St. Sebastian's," he said.

Now Caleb, in his turn, is "shining at the school," Bert Casiano said.

Moran spoke similarly, describing Caleb as "a phenomenal talent."

"You can tell a big part of that is how much work he puts into it because he's wanted it for so long," Moran said.