"He's the ultimate crooner who outlasted all his contemporaries," musician and longtime friend Gabriel Guerrero said from his Oregon home. Martin recently sang to Guerrero over the telephone.
"He has truly remained the 'Butterscotch Baritone' until he was 98," Guerrero added.
Although he never became a movie star, Mr. Martin was featured in 25 films, most of them made during the heyday of the Hollywood musicals, and he was often cast as the romantic lead.
He married two movie musical superstars, Alice Faye and Cyd Charisse, and the latter union lasted 60 years, until her death in 2008.
Mr. Martin found his escape through music while growing up in San Francisco and Oakland, Calif., amid a poor, close-knit Russian Jewish family, enduring taunts and slights from gentile classmates.
Performing on radio led to his break into the film business. His first singing role came in the 1936 Sing Baby Sing, which starred future wife Faye and introduced the Ritz Brothers to the screen as a more frenetic version of the Marx Brothers.
Mr. Martin had fallen in love with Faye while at Fox, where she was one of the studio's biggest stars. Married in 1937, the newlyweds were considered one of Hollywood's handsomest couples. But the marriage eroded because of career conflicts and his distaste for being known as Mr. Alice Faye. They divorced after two years.
He met Charisse, then a rising dance star at MGM, when they were dinner partners at a party given by their mutual agent. Just returned from the war, Mr. Martin was busy greeting old friends and paid her little attention.
They didn't meet again until a year later, when the persistent agent arranged another date. This time they clicked, and they married in 1948. She had a son, Nicky, born of her first marriage to dance director Nico Charisse. She gave birth to Tony Jr. in 1950.
Mr. Martin and Charisse put out a 1976 double autobiography, The Two of Us, and often toured in a singing and dancing shows. He continued appearances into his 90s.
Mr. Martin is survived by his stepson. - AP