German opera house drops Holocaust theme after disastrous premiere May 10, 2013 -- Updated 1355 GMT (2155 HKT) The opera house restaged the show as a concert after opening-night complaints Some people were said to be so horrified by the premiere they needed medical help Shocking scenes in the opening show included a Nazi-era firing squad and gas chamber Director Burkhard Kosminski did not want to change the staging, the opera house said (CNN) -- A German opera house forced to ditch its Holocaust-themed staging of a Wagner opera after it horrified the opening night audience said Friday that the decision to perform it only as a concert had gone down well with the public. The concert version of the production, featuring only the orchestra and singers, was performed at the Oper Am Rhein in Duesseldorf for the first time Thursday night. Scenes involving a Nazi-era firing squad and gas chamber during the Saturday premiere had left members of the audience reeling -- with some so badly affected that they needed medical help. Oper Am Rhein said Thursday that it had been aware from the outset that director Burkhard Kosminski's modern production of Richard Wagner's "Tannhauser" was "absolutely likely to arouse controversy." But, it said, the effects had gone beyond controversy, with "some scenes, especially the firing-squad sequence, which was staged with drastically realistic force" apparently proving an "intolerable burden for numerous members of the audience," both mentally and physically. As a result "they were subsequently obliged to undergo medical treatment," it said. After due consideration, the opera house said, "we have come to the conclusion that we cannot permit ourselves to undertake further responsibility for such an extreme effect caused by our artistic endeavors." German newspaper Der Speigel said in its English-language version that the production depicted "the character Tannhauser as a Nazi war criminal and it even included a gas chamber on stage." In what was a particularly shocking scene, it said, "nude actors are lowered to the floor on a cross made of glass cubes that are slowly filled with fog to represent the gas chambers." A spokesman for Oper Am Rhein, Daniel Senzek, told CNN Friday that many people had appreciated the decision to stage the production as a concert only. The opera house has offered refunds for any ticket holders who want their money back. Some people have requested refunds for their tickets, Senzek said, but was unable to give exact numbers. Other people bought tickets especially to see the concert version of the performance Thursday, he added. Oper Am Rhein said it had tried to negotiate with Kosminski over his staging after the disastrous premiere but he refused to modify his concept "for artistic reasons." It added: "Needless to say, we are obliged to respect the director's insistence on the protection of his artistic liberty." The production was supposed to explore Wagner's anti-Semitism and the influence the composer would have on Nazi ideology, Der Spiegel said. Tannhauser, which had its world premiere in 1845, is usually seen as a romantic work combining mythology and history.