[2] A pioneering scholar and performer of klezmer music, Sapoznik was the first director of the Max and Frieda Weinstein Archives of Recorded Sound at the YIVO Institute for Jewish Research, from its founding in 1982,[3][4] until 1994.
Murder Ballads and Disaster Songs 1913–1938 with Christopher King and authored the notes, which was nominated for a 2008 Grammy award for Best Historical Album.
[8] His most recent project with co-producer King is the 2 CD reissue box set Ernest V. Stoneman: The Unsung Father of Country Music 1925–1934 for 5 String Productions (2008).
[9] In his Wall Street Journal review, Nat Hentoff calls Sapoznik a "fount of historical and anecdotal knowledge of Yiddish culture and history".
[citation needed] Sapoznik was the director of the Mayrent Institute for Yiddish Culture at the University of Wisconsin–Madison, 2011-2018, and was also the donor of the Henry Sapoznik collection (AFC 2010/003), which includes photos, over 1400 sound recordings (most are instantaneous discs), and manuscript materials documenting Yiddish-American radio, at the American Folklife Center, Library of Congress.