For more than a decade, Wade M. Page, a former soldier who the police say was the lone gunman — and who was himself killed by a police officer on Sunday — played guitar and bass with an array of heavy metal bands that trafficked in the lyrics of hate.

Even in Mr. Page’s below-the-radar world, those bands — Blue Eyed Devils, Intimidation One and his own, End Apathy — provided a touchstone and a gateway to a larger cause, as they have for many others in recent years.

“It is one of the pillars of the white supremacist subculture,” Mark Pitcavage, director of investigative research at the Anti-Defamation League, said of white power music. “The message can motivate people to action, cause them to be proud of themselves and their cause. It can aggravate anger levels. It can rouse resentment.”

Two of Mr. Page’s bands make a cameo appearance in an F.B.I. informer’s report made public this year in a Florida drug investigation of people involved in white supremacist groups. The informer, who is not named, reported that the bands, Definite Hate and End Apathy, both played at a $20-per-person St. Patrick’s Day gathering of the Confederate Hammerskins group last year at a bar in rural Christmas, Fla.

Arno Michaelis, the former leader of a white power band called Centurion, whose CD “14 Words” has sold 20,000 copies worldwide, recalls being swept away when he heard racist music from the British skinhead group Skrewdriver in the 1990s.