Irwin Silber, who helped spark a resurgence of interest in American folk music during the 1950s and '60s with Sing Out!, the magazine he founded and edited for nearly two decades, and who publicly feuded over politics with folk singers Bob Dylan and Burl Ives, died Sept. 8 at an extended-care facility in Oakland, Calif. He was 84 and had Alzheimer's disease. Silber was a committed leftist and a onetime member of the Communist Party for whom music was an important political tool. In 1950, he joined forces with two like-minded partners, the musician Pete Seeger and musicologist Alan Lomax, to launch Sing Out!, a magazine about folk music that also served as a voice of dissent against Sen. Joseph McCarthy, R-Wis., and others leading a witch hunt into alleged communist subversion in politics and entertainment. The magazine's name comes from the lyrics of 'If I Had a Hammer,' a tune co- written in 1949 by Seeger and Lee Hays that became a universal protest anthem. In its first five years, the New York-based Sing Out! published about 400 new songs and old favorites, and it was the first to print such classics as Woody Guthrie's 'This Land Is Your Land' and 'Rock Island Line,' written by Kelly Pace and made famous by Lead Belly. As time went on, Silber embraced a broader and more diverse repertoire, publishing traditional African and Asian songs, gospel music and even Beethoven. With Silber at its helm, Sing Out! helped drive the folk music renaissance in the 1960s, as acoustic guitars and finely spun harmonies became instruments of the anti-Vietnam War counterculture. The magazine's early coverage of singers including Joan Baez, Judy Collins and Dylan helped launch them to national prominence. Silber served as editor until 1967, by which time the magazine's circulation had topped 25,000. He was a leading gatekeeper of the folk establishment, using his platform in Sing Out! both to highlight musical developments and reinforce the movement's left-leaning politics. Forceful and occasionally abrasive, he skewered those who he believed had abandoned their principles. He reprimanded Dylan for departing from his roots as a politically motivated singer, writing in 1964 that the folk star's 'new songs seem to be all inner- directed now, inner-probing, self-conscious.' Folk music observers have said Silber inspired Dylan's song 'Positively Fourth Street,' whose lyrics read: 'You say I let you down. You know it's not like that./If you're so hurt, why then don't you show it?' Another of Silber's targets was Ives, who voluntarily appeared before a U.S. Senate subcommittee in 1952 to dispel rumors that he was a Communist sympathizer. Ives named four closet Communists working in the music business, and Silber pounced. 'The well-known folksinger, who once joined in singing `Solidarity Forever,' has a different tune today. It might be called `Ballad for Stoolpigeons,' ' he wrote of Ives. 'The future of Burl Ives should be interesting. We've never seen anyone sing while crawling on his belly before.' Irwin Silber was born Oct. 17, 1925, to Jewish working-class parents in New York. He was a camper and then a counselor at a Marxist summer camp in New Jersey called Camp Wo-Chi-Ca and was a member of the Young Communist League. After graduating from Brooklyn College in 1945, he went to work for People's Songs, an organization that used a quarterly magazine, Bulletin, to promote music as a force for workers in their struggle for more rights and better treatment. Sing Out! grew out of People's Songs, which folded in the late 1940s. Silber's first marriage ended in divorce, as did his second, to the former Sylvia Kahn. Survivors include his wife of 33 years, jazz singer Barbara Dane of Oakland; three children from his second marriage, Frederic Silber of Redmond, Wash., Joshua Silber of New York and Nina Silber of Needham, Mass.; three stepchildren, Jesse Cahn of Luther, Okla., Pablo Menendez of Havana and Nina Menendez of Oakland; four grandchildren; and a great-grandson. After his tenure at Sing Out!, Silber became executive editor of the Guardian, a radical weekly publication. He also wrote several books, including 'Socialism: What Went Wrong?' and, more recently, 'A Patient's Guide to Knee and Hip Replacement.' 