By George P. Hassett

A 14-year-old Somerville boy was strangled with a piano chord in music class at the Winter Hill Community School on Friday, according to police.

The victim was sitting at a piano in class when another student approached and strangled him in front of the class, police said. The music teacher tried to pull the suspect away from the victim and screamed, "Stop," police said.

The juvenile, also 14, continued to choke the victim over the screams, police said. He was arrested and charged with assault and battery with a dangerous weapon.