Joseph Mlotek was born in the town of Proszowice, Poland, and moved with his family to Warsaw at the age of 7. As a young man, he was active in the Bund and other Jewish labor and socialist organizations. He also published Yiddish poetry in newspapers. He spent World War II in Shanghai and moved to the United States in 1949.
Mlotek was for a longtime director of the Workmen's Circle Yiddish school system, he published several collections of Yiddish songs with his wife, Chana Mlotek. The most recent collection was titled 'Songs of Generations.' He was also an editor of the Yiddish Forward newspaper.
Full biography of Joseph Mlotek could be viewed at the Mlotek family website
See also:
An interview with Joseph Mlotek: 'Joseph Mlotek: Oral History Memoir'. (June &Aug. 1984). William E. Wiener Oral History Library of the American Jewish Committee at 'New York Public Library'.
Joseph Mlotek's list of publications in the National Library of Israel.