To this day, Rachel Dratch is a bit surprised that Sandi Peaslee — “Mrs. P.” to her students — put up with her behavior in chorus class at Lexington High School.
It was nothing terrible, just the mildly distracting behavior of a hyperactive teenager who couldn’t stop making her classmates laugh.
Long before she became a star on “Saturday Night Live” Dratch was appearing in school productions of “No No Nanette’’ and “The Music Man,” under the tutelage of Peaslee, an inspiring teacher who combined a drive for perfection with the sensitivity to embrace complicated adolescents.
Obviously Dratch was an exceptional performing talent, but that was never the point in Peaslee’s classes. “Over the years I had teachers who were constantly separating out who was talented and who wasn’t,” Dratch said in a telephone interview. “She was never like that. I just remember her always being encouraging. We didn’t know how good we had it until we went out into the world.”
Sunday, Dratch will be one of over 100 former students who will participate in a concert in Peaslee’s honor at Lexington High.
Planned as a celebration, the concert has become a memorial.
Peaslee, who was diagnosed with stage 4 pancreatic cancer around Christmas, died on March 31, at 78. The show will go on in her memory, with concert proceeds benefiting one of her favorite charities, FOLMADS (Friends of Lexington Music, Art, and Drama Students).
The cast will draw together students Peaslee taught between 1963 and her retirement in 1993.
Peaslee was practically a one-woman performing arts department for decades. She was a gifted pianist and harpsichordist who worked with students across a broad musical spectrum. Her former students include Broadway performers, choral conductors, and rock musicians, such as Amanda Palmer. Her encouraging but firm tutelage clearly left a mark on Lexington students.
And like any great teacher, she is remembered for far more than her ability to impart subject matter.
“I really don’t think I would have made it through high school without her,” said Arnold Lee, one of the organizers of the concert. Three decades after high school, he now conducts two choral groups in the Bay Area. “I, like many high school students, had issues at home,” Lee said, and Mrs. P helped guide him.
Besides teaching him in chorus, he said, Peaslee set him on the path to becoming a conductor. “Sandi Peaslee was a teacher who could change lives — save lives, really. I wouldn’t be a quarter of the person I am without her.”
After the diagnosis, some former students asked if they could post the news on Facebook. Then a few had the idea that they would sing for her — maybe 20 of them, whomever they could round up. The outpouring of interest was so intense that it quickly became a full-blown concert, which Peaslee played a major role in planning.
Jeff Leonard, the director of music for the Lexington Schools and a former colleague, said Peaslee had fully intended to be at the show. But chemotherapy was so devastating that she stopped it, and she quickly declined after that.
“She went through three weeks of chemo and it just ruined her, “ Leonard said. “So as she often did, she did things on her own terms.”
Peaslee had prepared remarks for the closing of the show, which she dictated into a cellphone when she realized she wouldn’t make it. That recording, which will be played Sunday, is full of thanks for others, her friends say. Some who’ve heard it think it’s far too modest.
The concert promises to be part reunion, part tribute, and part memorial. “As humans and as artists our job is to really reach out to people and to create the opportunity for people to feel,” Leonard said. “Art is not always happy and it is not always sad. It runs the gamut. I think we will run that gamut of emotion on Sunday.”Adrian Walker is a Globe columnist. He can be reached at email@example.com.