The Judah Magnes Museum, located in Berkeley, California is open to the public. The Library contains Jewish recorded music and sheet music. Among the collections are a large number of 78 recordings. The Museum asks researchers to phone first and make an appointment at 510-549-6939. They are generally open Sundays–Thursdays, but closed on Jewish and Federal holidays, and are located at 2911 Russell Street, Berkeley, CA 94705.
http://www.jfed.org/magnes/magnes.htm