According to Lancaster Online, Groff — a Conestoga Valley alum — was asked to visit the students and attend the annual sing-along by his mother, Julie Groff, a physical education teacher at Conestoga Valley.
Groff, who was Tony-nominated for his performance in Spring Awakening, has also been seen on Broadway in In My Life and on television in "Glee." He will appear in the HBO series "Looking." Watch the trailer here.
Watch Groff sing with the students below: