A subway slashing in The Bronx that left a man with severed wrists started over loud music, according to a criminal complaint.

“Turn your music down, you f–king f—-t,” Runadieo Jordan, 52, allegedly yelled at his 31-year-old victim on a No. 2 train near Third Avenue and 149th Street around 1 a.m. Wednesday, the document says.

The victim responded, “What did you say to me?” the complaint states.

That’s when Jordan allegedly pulled his knife and cut the man on his right wrist.

The victim was left with severed arteries that have required him to undergo two surgeries, and he still has limited use of his wrist, the document states.

Jordan fled the train after the attack but was arrested a day later on suspected heroin possession in Manhattan — and then charged in the slashing while still in custody on the drug rap, officials said.

He was hit with a litany of charges in the transit case, including assault, criminal possession of a weapon and aggravated harassment, court records show.

After his arrest, the defendant was shown surveillance of himself and said, “Yeah that’s me. I ride the trains all the time. What of it?” according to the criminal complaint.