The fight erupted before 10 p.m. Saturday at an intersection near Luke Easter Park, the venue for the eighth annual Unity in the Park festival. Police didn't have a description of the shooter, and no arrests had been made.
It was unclear how long after Clinton or the other musicians performed that the shooting erupted or what prompted it. Police said they didn't know if those involved in the fight were among concertgoers leaving the area.
"These were younger people, so we're not sure," police Sgt. Sammy Morris said. "George Clinton is an older (artist). We're not going to speculate."
A 16-year-old boy with a gunshot wound to the head died of his injuries early Sunday, Morris said. He didn't know the conditions of the other three who were wounded: a 20-year-old woman shot in the neck, and a 14-year-old boy and a 23-year-old man each hospitalized with leg wounds.
The Cleveland Plain Dealer newspaper reported earlier that the two most seriously wounded were in critical condition and the other two were stable.
The newspaper said thousands of people had gathered for the festival, which featured George Clinton & Parliament Funkadelic as the headline act.