Some of the most prominent folk singers of the twentieth century like Pete Seeger, Woody Guthrie and Bob Dylan were being surveilled and, in some cases, blacklisted by the FBI due to their political activism and ties to the U.S Communist Party. Writer and historian Aaron J. Leonard has written several books on the subject and is in to reveal why the US Government was so fixated on musicians in the 1940s and 50s, and what he unearthed from the FBI files he gained access to.  Aaron J. Leonard's books on this subject include The Folk Singers and the Bureau: The FBI, the Folk Artists and the Suppression of the Communist Party, USA-1939-1956 and Whole World in an Uproar: Music, Rebellion and Repression - 1955-1972, both published by Repeater Books.