Amid a “Golden Age of Jewish Music,” in Berlin, Hersch Lewin, who ran a shop selling books, Judaica and gramophone records, founded his own label, Semer, in 1932. The timing was bad, as the Nazis came to power a year later and banned Jewish musicians performing in non-Jewish settings. Sixty years later, musicologist Dr. Rainer E. Lotz began scouring the world for Semer recordings. And in 2012, the Berlin Jewish Museum commissioned Alan Bern to create new interpretations of the archival recordings recovered by Lotz. The contemporary Semer Ensemble — featuring Bern, Lorin Sklamberg (The Klezmatics), Paul Brody, Daniel Kahn and other Jewish music luminaries — can be enjoyed on a new album of old tunes, Rescued Treasure (Piranha Records), which was recorded live over three nights last year at the Maxim Gorki Theater in Berlin. The album provides a wondrous journey into a lost world of European Jewry and heartfelt songs. — M.S.