From the website:

"Located in the Rare Book and Manuscript Library of the University of Pennsylvania, The Robert and Molly Freedman Jewish Sound Archive currently contains over 3800 recordings, primarily in Yiddish and Hebrew. Over 33.000 entries in the trilingual database catalog include the title of each track or band of the recording, author(s), composer(s) where known and performers."

Users can also listen to sample recordings of the collection online.