Teenage murder victim Isaac Stone was killed by a stab wound that penetrated deeply into his chest - as he tried to block the blade - a jury heard today.
Isaac, a rapper who performed under the name Dynamikk, suffered 11 cut and slash wounds to his body in what prosecutors told Luton Crown Court was a "murderous attack" in a Bedford street.
His friend Shajidur Rahman also received four deep slashes to his head and face - with his nose effectively being amputated.
Giving evidence today, pathologist Nicholas Hunt said the cause of the 19-year-old's death was a stab wound that penetrated deeply into his chest.
Dr Hunt said he also found 10 other injuries to Isaac's scalp, back, chest, side, buttock and hand.
The injuries to his left hand were consistent with defensive injuries caused when he tried to grab a blade or block it.
The pathologist said it was "beyond reasonable doubt" that the fatal wound could not have been caused by a meat cleaver that was found at the scene.
The attack took place on January 25 this year at Costain Street in Bedford.
Earlier in the trial, prosecutor Vincent Coughlin QC said the motive for attack was not entirely clear but came after an amateur music video called "Go Missing" was posted on YouTube in which Mr Stone, Mr Rahman and others appeared.
"It upset someone," said Mr Coughlin.
Mohammed Hussain, 22, of Maitland Road, Bedford, 19 year old Rubel Miah, of Costin Street, Bedford, his brother Javed Miah, 21, also of Costin Street, Bedford and Fahim Khan, 20, of Fenlake Road, Bedford, are all accused of murder, attempted murder and two counts of possession of an offensive weapon.
Mr Coughlin said: "These four defendants involved themselves in a fast-moving, violent and savage street brawl with another group of young men."
He said that "perhaps for show" some of the defendants had gone to Luton to hire a white Range Rover for £150.
Back in Bedford they went to a hardware shop in Greenhill Street, where they bought two meat cleavers.
Isaac Stone, who was driving a white Corsa with Mr Rahman and two others as passengers, encountered the other group in Costin Street, the court was told.
All four defendants deny the charges. The case continues.