During the Cold War, listeners in captive nations behind the Iron Curtain huddled around radios in basements and attics listening to the imposing bass-baritone voice of the man who sent them American music. His greeting—“Good evening, Willis Conover in Washington, D.C., with Music U.S.A.”—was familiar to millions around the world. At home, relatively few people knew him or his work. A proposal for a postage stamp honoring Conover may give hope to those who want the late Voice of America broadcaster to be awarded a larger mark of distinction.

For 40 years, until shortly before his death in 1996, Conover’s shortwave broadcasts on the Voice of America constituted one of his country’s most effective instruments of cultural diplomacy. Never a government employee, to maintain his independence he worked as a freelance contractor. With knowledge, taste, dignity and no tinge of politics, he introduced his listeners to jazz and American popular music. He interviewed virtually every prominent jazz figure of the second half of the 20th century. His use of the VOA’s “special English”—simple vocabulary and structures spoken at a slow tempo—made him, in effect, a teacher of the language to his listeners.

Countless musicians from former Iron Curtain countries have credited Conover with attracting them to jazz, among them the Czech bassists George Mraz and Miroslav Vitous, the Cuban saxophonist and clarinetist Paquito D’Rivera and the Russian trumpeter Valery Ponomarev. On the Conover Facebook page established in 2010, Ponomarev wrote that Conover had done as much for jazz “as Art Blakey, Duke Ellington, Horace Silver, Count Basie, Charlie Parker, Miles Davis and Dizzy Gillespie.” Conover’s New York Times obituary said, “In the long struggle between the forces of Communism and democracy, Mr. Conover, who went on the air in 1955 . . . proved more effective than a fleet of B-29’s.” In his publication Gene Lees Jazzletter, the influential critic wrote, “Willis Conover did more to crumble the Berlin Wall and bring about the collapse of the Soviet Empire than all the Cold War presidents put together.”

In its Dec. 9, 1966, issue, Time magazine quoted Conover on the importance of the music he championed. “Jazz tells more about America than any American can realize. It bespeaks vitality, strength, social mobility; it’s a free music with its own discipline, but not an imposed, inhibiting discipline.”

When Conover visited Eastern Europe and the U.S.S.R.—Poland for the first time in 1959, the Soviet Union and Czechoslovakia in 1965—huge crowds gathered to greet him as a hero. But thanks to the Smith-Mundt Act of 1948, which forbids the VOA from broadcasting within the U.S., only Americans who snagged VOA shortwave signals directed overseas knew Conover’s programs. Attempts to persuade Presidents Clinton, Bush and Obama to posthumously award Conover a Presidential Medal of Freedom have yielded no result.