performed jazz music, and Viktor Ullmann composed more than 20 works while imprisoned at Theresienstadt, including the opera Der Kaiser von Atlantis. The children's opera Brundibár, composed in 1938 by Hans Krása, was first performed at Theresienstadt on 23 September 1943. A hit, it was performed 55 times (about once a week) until the transports of autumn 1944. The work of the musicians was exploited by the Nazis in the two propaganda films made in the ghetto. Only the social elite could get tickets for events, and attending musical and theatrical performances became a status symbol. The visual arts were developed by a circle of artists, including Bedřich Fritta, Norbert Troller, Leo Haas, Otto Ungar, and Petr Kien, who were officially employed by the Arts Department of the self-administration to create drawings and graphs of work at Theresienstadt on the orders of the SS. The artists, however, depicted the ghetto's actual conditions in their spare time. Several of these artists were caught smuggling their work out of the ghetto. Accused of "atrocity propaganda", they were arrested on 20 July 1944 and tortured at the Small Fortress. Much of their artwork was not rediscovered until many years later, but has been a useful tool for historians to glimpse the ghetto elite as well the widespread misery in the ghetto. The Ghetto Central Library opened in November 1942 and contained 60,000 books and 15 full-time librarians by the end of 1943. As head of the library, the Central Secretariat appointed the philosopher Emil Utitz, who individually approved borrowers. It eventually grew to over 100,000 volumes from Jewish libraries all over Europe or brought by prisoners to the ghetto. The library was criticized for the high proportion of Hebrew-language works and the lack of fiction, but prisoners were desperate for any kind of reading material. At least 2,309 lectures were delivered in the ghetto, on a variety of subjects including Judaism, Zionism, art, music, science, and economics, by 489 different people, leading the ghetto to be described as an "open university". Theresienstadt was the only Nazi concentration center where religious observance was not banned. Although they were all Jewish according to the Nuremberg Laws, deportees came from a wide variety of strains of Judaism and Christianity; others were atheists. Some communities and individuals, particularly from Moravia, brought their Torah scrolls, Shofar, tefillin, and other religious items with them to the ghetto. Edelstein, who