The brothers joined Bing Crosby in recording the hit "Swinging on a Star" in 1944 for Crosby's film "Going My Way," and Andy, barely a teenager, was picked to dub Lauren Bacall's voice on a song for the film "To Have and Have Not." His voice stayed in the film until the preview, when it was cut because it didn't sound like Bacall's.
Later the brothers worked with Kay Thompson of eventual "Eloise" fame, then a singer who had taken a position as vocal coach at MGM studios, working with Judy Garland, June Allyson and others. After three months of training, Thompson and the Williams Brothers broke in their show at the El Rancho Room in Las Vegas to a huge ovation. They drew rave reviews in New York, Los Angeles and across the nation, earning a peak of $25,000 a week.
Williams, analyzing their success, once said: "Somehow we managed to work up and sustain an almost unbearable pitch of speed and rhythm."
After five years, the three older brothers, who were starting their own families, had tired of the constant travel and left to pursue other careers.
Williams initially struggled as a solo act and was so broke at one point that he resorted to eating food intended for his two dogs.
"I had no money for food, so I ate it," he recalled in 2001, "and it actually was damned good."
A two-year TV stint on Steve Allen's "Tonight Show" and a contract with Cadence Records turned things around. Williams later formed his own label, Barnaby Records, which released music by the Everly Brothers, Ray Stevens and Jimmy Buffett.
Williams was a lifelong Republican who once accused President Obama of "following Marxist theory." But he acknowledged experimenting with LSD, opposed the Nixon administration's efforts in the 1970s to deport John Lennon and in 1968 was an energetic supporter of Robert Kennedy's presidential campaign. When Kennedy was assassinated in Los Angeles in June 1968, just after winning the California Democratic primary, Williams sang "The Battle Hymn of the Republic" at his funeral.