(CNN) -- Singer Wayne Mills, whose "outlaw country" songs center on honky-tonk life, died in a Nashville bar shooting Saturday, police said.
Chris Ferrell, owner of Nashville's Pit and Barrel bar, told police he shot Mills, 44, in self-defense, according to a Nashville police statement.
"Wayne Mills by definition is one that is a stiff-necked, country troubadour with an affinity for honky-tonks and possessing a style of rustic simplicity," his official website said.
He's an "average country boy steeped in the Southern vernacular of God, guns and football," his official biography reads.
Investigators say Mills and Ferrell, 44, were in the closed bar with "a few friends and acquaintances" when the two men -- who were friends -- "began to argue and the others left."
Police are investigating Ferrell's claim that the shooting was justified by self-defense.
Mills, who leads the Wayne Mills Band, died at Vanderbilt University Medical Center in Nashville hours after the shooting, according to band manager J.R. Smith
Smith told CNN that Mills suffered a bullet wound to his head.
"I hope justice is served," Smith said.
Mills grew up in the north Alabama town of Arab, Smith said. He played baseball at Wallace State Junior College and football at the University of Alabama, where he earned an education degree, before becoming a professional musician.
Mills had been working on his seventh album, "Long Hard Road," and touring small Southern venues.
His next gig had been scheduled for Saturday night at Granddaddy's Lounge in Ramer, Alabama.
CNN's David Daniel contributed to this report.