At its height, the Voice of America Jazz Hour was listened to by up to 30 million people.
Although the Voice of America was prohibited from broadcasting in the United States by the Smith-Mundt Act, the shortwave signal was receivable in the US and had a sizable USA audience.
As jazz was frequently banned in the Soviet Union and its satellite countries, Voice of America was often the only way people in those countries could listen to jazz.
Willis Conover's politics-free broadcasts are widely credited for keeping interest in jazz active in Soviet satellite states.
[3] In addition, Conover's clear, measured pronunciation when hosting the Jazz Hour is sometimes credited for leading to the development of Special English in 1959.