The smooth harmony of “Sleigh Ride” rang out from the auditorium yesterday morning, drawing the attention of curious students. Teachers hummed along as they picked up food from the table in the back.

On Dec. 18, faculty members were invited to an annual holiday concert, hosted by the performing arts department as a special substitute for the usual lecture-style meeting. This year, band students and members of the “Sweeney Todd” cast arrived at school early to perform before the start of first period.

“We performed the finale from the show for the faculty,” choral director Molly Khatcheressian said. “And, by special request, we killed Dr. Glazer in the song again.”