"She pushed me real hard," he said. "I hit some part of the equipment on the way down to the floor."
Chambers believes the attack was racially motivated. He described Andrews-Potter as appearing "evil."
"She had the look of hate in her face," he said. "Police said she was disturbed by the repitition of the lyrics I was singing."
Police cited and released the woman at the scene. Last week, prosecutors charged her with felony assault and elder abuse.
Andrews-Potter could not be reached Tuesday.
Chambers filed his suit Monday in Alameda County Superior Court. In addition to naming Andrews-Potter, it accuses the Bay Area Blues Society of providing weak security and says the city was negligent for not reviewing security plans, said Chambers' lawyer, John Burris.
A private security firm may be added to the list of defendants at some point, he said.
Michael Lawson, Hayward's city attorney, declined to comment on the suit in a story by the Oakland Tribune. He said the city is reviewing a related but separate $5 million claim, also filed Monday.
Officials from the blues society could not be reached Tuesday.
Meanwhile, Chambers said his recovery could take a year. He said the swelling has gone down but he has a sore back and scar tissue on his left rib cage that affects his breathing.